Poisons: The Perfect Murder Weapon with DP Lyle, MD
MWA Rocky Mountain Chapter Event on YouTube
Many thanks to the MWA Rocky Mountain Chapter for hosting this event and asking me to do it.
Poisons: The Perfect Murder Weapon with DP Lyle, MD
MWA Rocky Mountain Chapter Event on YouTube
Many thanks to the MWA Rocky Mountain Chapter for hosting this event and asking me to do it.
Criminal Mischief: Episode #34: Toxicology Part 3
PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html
From HOWDUNNIT: FORENSICS
COMMON DRUGS, POISONS, AND TOXINS
In the remote past, most poisoners favored botanical products such as hemlock, oleander, deadly nightshade, foxglove, hellebore, monkshood, opium, and many others. These were easily available and untraceable. More recently, various chemicals have been added to this long list of plant-based poisons, which has made the work of the toxicologist that much more difficult.
I said earlier that when the forensic toxicologist is faced with determining whether an individual’s death or abnormal behavior is related to toxin exposure, he will use all evidence, including the results of toxicology testing, the autopsy examination, and statements from investigating officers and witnesses. To effectively use this information, he must be familiar with many aspects of drugs and poisons: He must know the chemical makeup and physiological actions of drugs and their breakdown products; understand how drugs are metabolized in the body and what the potential toxic properties of these metabolites are; know how these chemicals affect a normal person, as well as those with various illnesses and addictions; and be aware of the symptoms and signs produced by these chemicals. In addition, a working knowledge of street and recreational drugs is essential, since these are often involved in injury and death.
Obviously, a discussion of every known chemical, drug, and poison is far beyond the scope of this book. We will, however, look at many of those that crop up in real-life cases as well as in works of fiction.
We will examine the things that the ME and the toxicologist consider in assessing the effects of any of them in death, injury, or legal matters. For example, some drugs cause severe depression or addiction and may lead the user to take his own life. Others may distort perceptions to the point that the user accidentally causes self-harm through some foolish act. Trying to fly from a building would fit this description. Other drugs may cause anger, aggression, or an actual psychotic episode, and the user may commit assaults or homicides while under the chemical’s influence. Some drugs are so addictive that the user will commit all types of illegal acts (robbery, assault, or murder) to obtain money to purchase them. Other substances are just downright deadly.
Alcohol is derived from the fermentation of sugars and comes in a variety of types, with ethanol (ethyl, or drinking alcohol), methanol (methyl, or wood or denatured alcohol), and isopropanol (isopropyl, or rubbing alcohol) being the ones most commonly encountered. All alcohols are central nervous system (CNS) depressants. Central nervous system basically means the brain. These alcohols cause sleepiness, poor coordination, slowed movements and reactions, and distorted perceptions. In short, all the symptoms and signs you recognize in someone who is drunk. In larger amounts, they can lead to coma, cessation of breathing, and death from asphyxia.
Ethanol is by far the most commonly abused drug. Not only are its toxic effects potentially lethal, but the loss of coordination and poor judgment that is associated with its use can lead to violent and negligent acts. There is potential for physical addiction with alcohol and withdrawal can be an arduous and dangerous process. Without proper medical treatment, death rates from alcohol withdrawal syndromes, such as delirium tremens (DTs), can be 20 percent or more.
Alcohol in the body follows a fairly simple pathway. Once ingested, it is absorbed into the bloodstream and disseminated throughout the body, where 95 percent of it is metabolized (broken down) by the liver into water and carbon dioxide. The remaining 5 percent is excreted unchanged through the kidneys and lungs, a fact that is critical to sobriety testing.
The body eliminates most toxins in what is called a dose-dependent fashion; that is, the higher the dose taken, the more rapidly the toxin is metabolized. A small amount activates only some of the enzymes that break down the toxin, whereas a larger amount activates more enzymes in order to handle the increased load of toxin.
Alcohol is metabolized in a linear fashion in that any amount of alcohol intake activates all the enzyme systems that destroy it. This means that from the first drink, the system operates at almost maximum efficiency and there is little or no ability to increase it. The average rate of ethanol destruction in the body is roughly equivalent to one drink per hour.
Why is this important? With rapid intake of alcohol, as is seen in binge drinking that is so common among college students, the body has no method for increasing the removal of the alcohol. The system is already running at top speed and excessive intake overruns the body’s ability to deal with it. The result is that the concentration of alcohol in the blood will rise rapidly and this can lead to coma and death.
All alcohols are potentially toxic, but methanol is particularly so. Methanol is the denatured alcohol used in Bunsen burners in high school science or chemistry classes. Unlike ethanol, the liver converts methanol to formic acid and formaldehyde, the same stuff the coroner uses to preserve the tissues he removes from corpses.
Methanol ingestion causes nausea, vomiting, pancreatic and other organ damage, confusion, loss of coordination, and brain damage that can lead to blindness, seizures, coma, and ultimately death from asphyxia.
Isopropanol is also an intoxicant and a CNS depressant whose effects usually appear within ten to thirty minutes after ingestion, depending upon the amount consumed and whether food or other beverages are taken as well. Fifteen to 20 percent of ingested isopropanol is converted to acetone, which produces acidosis (excess acid in the body). This greatly complicates things. The victim appears drowsy and off balance, and possesses a staggering gait, slurred speech, and poor coordination. Nausea, vomiting (sometimes bloody), abdominal pain, sweating, stupor, coma, and death from respiratory depression may follow. Hemorrhage into the bronchial tubes (breathing tubes or airways) and chest cavity may occur.
Isopropanol also absorbs through the lungs and the skin. Not infrequently, infants experience isopropanol toxicity from alcohol-and-water sponge baths used to treat childhood fevers.
OTHER CNS DEPRESSANTS
Opiates, barbiturates, and other tranquilizers are CNS depressants. They make a person sleepy and lethargic and are called downers.
Opiates are in the alkaloid family of chemicals and are derived from the sap of the poppy. The opiates are divided into natural, semisynthetic, and synthetic, depending upon their source and method of manufacture. They are narcotic sedatives (sleep producing) and analgesics (pain relieving) that produce euphoria, lethargy, and, in larger doses, coma and death from respiratory depression and asphyxia. This is more common when an opiate is mixed with alcohol, which is also a brain depressant. Most opiates are taken either by mouth or injection, and all have great potential for abuse and physical addiction.
Natural opiates come directly from the poppy with morphine, a powerful narcotic much like heroin, and codeine being the basic ones. Codeine is found in many cough suppressants, has a low potential for abuse, and, unless used with alcohol, rarely causes death. Combining morphine with acetic anhydride or acetyl chloride produces heroin (diacetylmorphine), which is by far the most commonly abused opiate.
After injection, heroin is almost immediately broken down into monoacetylmorphine and then to morphine. In the living user, testing typically only reveals morphine since this two-step conversion process occurs fairly quickly. This means that the testing cannot determine if the person used heroin or morphine, since in either case only morphine would be found.
The autopsy findings in individuals who die from a heroin overdose are fairly consistent. The ME usually, but not always, finds evidence of pulmonary edema, which is water in the lungs. The lungs often show evidence of talc crystals and cotton fibers, as these are used to cut and filter the heroin, respectively. When the drug is given intravenously, these crystals and fibers are carried through the right side of the heart and are filtered from the blood and trapped by the lungs.
Semisynthetic opiates are created by molecular alterations of morphine and codeine. Many medical analgesics are of this type. Hydrocodone, oxymorphone, and oxycodone (OxyContin) are examples.
Synthetic opiates are constructed in a laboratory and are not derived from either morphine or codeine. Methadone is the best known of this class because of its use in treating heroin addiction. Other synthetic opiates include meperidine (Demerol) and fentanyl drugs.
Barbiturates are derived from barbituric acid. Known as hypnotics (sleeping pills), they include pentobarbital, amobarbital, secobarbital, butabarbital, and phenobarbital. Only phenobarbital, an excellent anticonvulsive (prevents seizures) medication, is widely used today. When mixed with alcohol, barbiturates can readily lead to coma and death from asphyxia.
Stimulants or “uppers” are a commonly abused class of drugs that rev up the nervous system and pump up the blood pressure and heart rate. The ones most commonly used are amphetamines and cocaine. These drugs increase alertness, lessen fatigue, and suppress appetite. However, with continued use, they cause irritability, anxiousness, aggressive behavior, paranoia, fatigue, depression, and death.
Chronic users tend to develop tachyphylaxis. This means that the body “gets used to” them and their effects are lessened. The user must take ever-increasing amounts to get the same “kick” because the body produces more of the enzymes that metabolize these drugs so that they are destroyed and eliminated at a faster rate.
Amphetamines belong to the phenethylamine class of chemicals and are what we term sympathomimetics, in that they mimic, or act like, the sympathetic side of the autonomic nervous system. This is the fight or flight response. Amphetamines rev up the body for emergency action. To do this, they increase blood pressure, heart rate, and respiration, and produce euphoria and a sense of high energy.
Cocaine is a CNS stimulant that increases alertness, elevates blood pressure and heart rate, and raises body temperature. In higher amounts, it can lead to seizures, strokes, heart attacks, and death.
Typically, cocaine is snorted, or inhaled through the nose. When introduced this way, it rapidly absorbs through the membranes that line the nose and enters the bloodstream. Its effects are felt in just a few minutes. As with amphetamines, cocaine has the problem of tachyphylaxis so the “high” tends to diminish with repeated use. So, abusers have found even faster ways of reaching the “high” they seek.
Cocaine can be mixed with baking soda and water, and heated until all the liquid is evaporated; the solid material remaining is crack cocaine. This form has a much lower boiling point (becomes a gas at a lower temperature), which allows it to be smoked. When inhaled, this gaseous form is very rapidly absorbed through the lungs and into the bloodstream.
Hallucinogens alter perceptions and mood, lead to delusional thinking, and cause hallucinations.
Delusions are beliefs that have little or no basis in reality. The person might believe that he is being watched or monitored or that his neighbor, boss, or spouse is trying to harm him.
Hallucinations are sensory experiences that are not real. That is, they are not an abnormal sensing of some sensory input; rather, the entire sensory experience is created within the person’s mind. These creations may involve any or all of the senses. They may be visual, auditory, olfactory, taste, or tactile. Sometimes these sensations are so real that the person can’t separate the hallucination from reality, or worse, the hallucination becomes the reality.
Hallucinations are part of severe schizophrenia and other mental disorders and can occur in victims of strokes or senile dementia. They are often seen with use and withdrawal from alcohol and other drugs. Hallucinogenic drugs are specifically designed to produce hallucinations.
The most frequently encountered hallucinogens come from the plant world (marijuana, peyote, and mushrooms) or the chemistry laboratory (LSD, STP, and PCP). Their identification depends upon both physical and chemical analyses.
By far the most commonly used hallucinogen, and one of the mildest, is marijuana. It goes by many street names including Mary Jane, weed, and pot. It is a cannabinoid, which means it is derived from the Cannabis sativa plant. The active ingredient tetrahydrocannabinol (THC) is found in marijuana at a concentration of 2 to 6 percent. Hashish is the oily extract of the plant and contains approximately 12 percent THC.
Though marijuana can be added to food and eaten, the most common method of introduction is through smoking. It is rapidly absorbed through the lungs, reaches peak blood levels in fifteen to twenty minutes, and usually lasts about two hours. It produces euphoria, sedation, loss of memory, reduced coordination, and also stimulates appetite.
The body breaks down THC into a series of compounds, the most important being 9-carboxy-tetrahydrocannabinol (9-carboxy-THC), which is the major urinary metabolite. Urine drug testing looks for this compound, which can be found up to ten months after last use. One problem is that even passive exposure can lead to a positive urine test. For example, if a person is in the area where someone is smoking marijuana, his urine may reveal low levels of 9-carboxy-THC.
Cacti and Mushrooms
Peyote is a small Mexican cactus that has enjoyed a ceremonial use by many native tribes for centuries. The active chemical in the plant is mescaline, which is a hallucinogen in the alkaloid family. Either TLC or GC can confirm the presence of the alkaloids. Further testing to identify mescaline is not necessary since the possession of plant material itself is illegal.
Mushrooms present a different problem. With marijuana and peyote the mere possession of the plant is illegal, while the possession of mushrooms is not. This means that the toxicology lab must identify the psychoactive components (psilcin and psilocybin) of the mushroom before they can be deemed illegal.
LSD AND OTHER HALLUCINOGENIC CHEMICALS
There are a wide variety of chemically produced hallucinogens, with the most common ones being lysergic acid diethylamide (LSD) and phencyclidine (PCP or angel dust).
LSD is very potent and as little as 25 micrograms can produce an “acid trip” that lasts for twelve hours. Though LSD is not directly fatal, the hallucinations it produces are typically vivid and there have been many instances of users harming themselves because of these altered perceptions. The primary screening test for LSD is the Van Urk color test.
PCP is an extremely powerful drug with unpredictable effects. It comes as a powder or in a capsule or pill. It can be swallowed or smoked. PCP can cause depression, irritability, feelings of isolation, and is notorious for producing psychosis, paranoia, and violent behavior. An acute schizophrenic episode may suddenly occur many days after use. In a large enough dose, it can cause seizures and death.
Immunoassay of urine is used for PCP screening and may remain positive for a week after last use. GC/MS provide confirmation.
Other chemical hallucinogens include dimethoxymethylamphetamine (STP), dimethyltryptamine (DMT), and methylenedioxymethamphetamine (MDMA), also known as ecstasy.
DATE RAPE DRUGS
The date rape drugs are a collection of chemicals of various types that share the ability to make the user relaxed, disoriented, and compliant. Some are pharmaceutically manufactured, while others are cooked up by someone with marginal experience and a chemistry book. The major members of this group are Rohypnol (flunitrazepam), ecstasy, GHB (gamma-hydroxybutyrate), and ketamine hydrochloride.
Rohypnol, GHB, and ketamine are commonly used in date or acquaintance rapes, which is where the moniker comes from. They cause sedation, a degree of compliance, poor judgment, and amnesia for events that occur while under their influence. These properties make them effective in date rape situations.
A small amount of GHB or Rohypnol can be slipped into the victim’s drink or a bottle of innocuous-appearing water. She may appear and act normally, or might seem happy, excited, pleasantly sedated, or mildly intoxicated. Neither the victim nor her friends recognize how impaired she actually is. She might leave with her would-be assailant because her judgment is impaired and euphoria enhanced. Only later will she realize that something happened, but her memory of events will be spotty or absent. This is exactly what happened with Andrew Luster’s victims.
The reactions to these drugs are unpredictable and vary from person to person.
Rohypnol (Street Names: Roofies, Roaches, Rope, Mexican Valium) is a benzodiazepine sedative in the same family as Valium and was developed to treat insomnia. Currently, it is neither manufactured nor approved for use in the United States, but is available in Mexico and many other countries. It is manufactured as white tablets of either one or two milligrams that can be crushed and dissolved in any liquid. It takes action twenty to thirty minutes after ingestion, peaks in about two hours, and its effects may persist for eight to twelve hours.
Rohypnol typically causes sedation, confusion, euphoria, loss of identity, dizziness, blurred vision, slowed psychomotor performance, and amnesia. The victim has poor judgment, a feeling of sedated euphoria, and vague or no memory of what has happened.
Ecstasy (Street Names: E, X, XTC, MDMA, Love, Adam) was first manufactured in 1912 and originally patented in 1914 as an appetite suppressant but was never marketed. It disappeared until the 1960s when it was rediscovered and became a drug of abuse. Currently, it is made in underground labs and distributed in pill or capsule form. It has amphetamine (speed-like) as well as hallucinogenic effects. The user has enhanced sensations and feelings of empathy, increased energy, and occasionally profound spiritual experiences or irrational fear reactions. It may cause increased blood pressure, teeth grinding (bruxia), sweating, nausea, anxiety, or panic attacks.
GHB comes as a white powder that easily dissolves in water, alcohol, and other liquids. Currently, it is often found as “Liquid E,” a colorless, odorless liquid that is sold in small vials and bottles.
The effects of GHB appear five to twenty minutes after ingestion and typically last for two to three hours. It causes loss of inhibitions, euphoria, drowsiness, and, when combined with other drugs, increases the effects of these drugs. Users might also experience amnesia, enhanced sensuality, hallucinations, and amnesia.
Ketamine is a rapidly acting intravenous or intramuscular anesthetic agent that causes sedation and amnesia. It comes as a liquid, which is often heated and evaporated to a white powder residue. The powder can be added to a liquid such as a bottle of water, compacted into pills, or, most commonly, snorted. Whether swallowed or snorted, it takes effect almost immediately and is fairly short in its duration of action, typically forty-five minutes to two hours.
Many of its effects are similar to ecstasy, but it also possesses dissociative effects, which means the person “dissociates” from reality in some fashion. Often the user experiences hallucinations, loss of time sense, and loss of self-identity. One common form is a depersonalization syndrome, where the person is part of the activities while at the same time is off to the side or hovering overhead watching the activity, including his own actions. As mentioned earlier, this reaction is also common with PCP. Users call these effects “going into a K Hole.”
Since ketamine is a sedative and general anesthetic, its potential for serious and lethal effects is real. If too much is taken, the victim may lose consciousness, stop breathing, and suffer brain damage or die.
Cyanide is one of the most lethal chemicals known and can enter the body by inhalation, ingestion, or directly through the skin. The most common forms are the white powders sodium cyanide (NaCN) and potassium cyanide (KCN) and the gaseous hydrogen cyanide (HCN). Most poisonings are accidental, but suicidal and homicidal cyanide poisonings do occur. HCN is used in gas chamber executions. Cyanide is a metabolic poison, which means it damages the internal workings of the cells.
Strychnine is a neuromuscular toxin that causes powerful convulsive contractions of all the body’s muscles. The body adopts a posture known as opisthotonos, which means the back is arched so that only the back of the head and the heels of the feet touch the floor. Death results from asphyxia, since breathing is impossible during such violent muscular contractions. At death, rigor mortis often occurs very quickly because the muscles are depleted of ATP during these contractions (see Chapter Five: Time of Death, “Rigor Mortis”). Strychnine is rarely used for homicide since its extremely bitter taste makes it difficult to disguise in food. It is occasionally used for suicide, but since it has the deserved reputation for being very painful, this is also rare.
Mushrooms were discussed earlier (see “Hallucinogenic Drugs”). But those of the psilocybin variety are not nearly as sinister as are the mushrooms of the Amanita family, such as the death cap and death angel mushrooms. These poisonous mushrooms have been implicated in accidental, suicidal, and homicidal deaths.
The death cap is so toxic that a single mushroom can kill. The two main toxins are amanitin, which causes a drop in blood sugar (hypoglycemia), and phalloidin, which damages the kidneys, liver, and heart. The real treachery of these mushrooms lies in that fact that the symptoms—nausea, vomiting, diarrhea, and abdominal pain—are slow to onset, typically beginning six to fifteen hours after ingestion, but can be delayed as much as forty-eight hours. In general, the later the onset of symptoms, the worse the chances for survival. This is because the toxins go to work on the liver and other organs almost immediately, but since symptoms are delayed for many hours, the victim doesn’t know to seek medical help until it is very late. At autopsy, the ME finds severe damage to the liver and the toxicologist might find a low level of sugar in the blood, as well as the amantin and phalloidin toxins.
Ethylene glycol is the major ingredient in many antifreeze solutions. In the body, ethylene glycol breaks down into several compounds, the most important being oxalic acid. When oxalic acid is absorbed into the bloodstream, it reacts with calcium in the blood to form calcium oxalate. This reaction consumes the blood’s calcium, and low levels can cause a cardiac arrest and death. The calcium oxalate is filtered through the kidneys where it can clog up the microscopic tubules and severely damage the kidneys. At autopsy, the ME finds the crystals in the tubules of the kidney. Oxalic acid is also found in raw (not properly cooked) rhubarb, which can lead to accidental poisonings. It is rarely if ever used for suicide or homicide. Ingestion of this plant can irritate the gastrointestinal tract and cause mouth, throat, and esophageal pain and possibly bleeding. In those who die from this plant, the autopsy reveals a burned and irritated mouth, esophagus, and stomach, low blood calcium levels, and calcium oxalate sludge in the kidneys.
Heavy metals are dangerous metallic elements such as arsenic, mercury, lead, bismuth, antimony, and thallium. Arsenic was the major homicidal poison for hundreds of years but is not frequently used now. One reason is that it works slowly. Even a large dose will take hours to kill someone. And since the death is very painful, the victim will often seek medical help before death and sur- vive. It is occasionally used as a chronic poison.
The most common arsenical compound used in homicidal poisonings is arsenic trioxide, which is a white powder. A dose of 200 to 300 milligrams is usually lethal. Symptoms begin about thirty minutes after ingestion and include nausea, vomiting, abdominal pain, bloody diarrhea, a metallic taste in the mouth, and a slight garlicky odor to the breath. Arsenic severely damages the lining of the stomach and intestines and the ME will easily see this at autopsy in those who die. He will also find fatty deposits in the liver, kidneys, and heart.
Lead poisoning is uncommon and usually occurs in an industrial setting. Occasionally children will peel away and eat wall paint that contains lead. Even though lead has not been a component of interior paints for decades, many older buildings still have layers of old lead-based paint. Lead poisoning can cause anemia, nausea, vomiting, abdominal pain, weakness, numbness, and seizures.
Insulin is a naturally occurring hormone that is essential for life. It is also synthetically manufactured and is a life-saving treatment for many diabetics. On occasion, diabetics die from an accidental overdose of insulin, but it has also been used for suicide and homicide. In fact, for many years it was considered to be an almost perfect murder weapon. The injection of a large dose dramatically drops the level of sugar in the blood, and since the brain needs a continuous supply of nutrition, death occurs very quickly. And since insulin is normally found in all of us, how could its presence raise suspicion? Now, insulin levels can be determined by radioimmunoassay and if the level at autopsy is found to be very high, the ME searches for a rare insulin-secreting tumor in the pancreas. If he finds no tumor, it is logical to suspect that insulin has been administered by someone else and the ME launches a search for hidden injection sites on the corpse.
Succinyl choline is an injectable drug that paralyzes every muscle of the body and prevents all movement, even breathing. Death is from asphyxia. It has also been considered a nearly perfect murder weapon.
After injection, it is very quickly metabolized by the body and leaves behind little evidence of its presence. However, since the 1980s the gas chromatography and mass spectrometry (GC/MS) combination has allowed for detection of the drug’s metabolites. If the ME suspects that this drug has been used, he takes blood samples as well as excises the tissues around any suspected injection sites and sends these materials to the toxicologist. Toxicological testing using GC/MS is directed toward finding metabolites of the drug, which, when found, proves that the drug was at one time present in the victim. This sophisticated testing was a direct result of the Carl Coppolino case.
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Criminal Mischief: Episode #32: Toxicology Part 1
PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html
From HOWDUNNIT: FORENSICS
WHAT IS A POISON?
The terms poison, toxin, and drug are simply different ways of saying the same thing. Though you might think that a poison kills, a toxin harms, and a drug cures, these terms can be used almost interchangeably. The reason is that what can cure can also harm, and what can harm can kill.
Anything and everything can be a poison. The basic definition of a poison is any substance that, if taken in sufficient quantities, causes a harmful or deadly reaction. The key here is the phrase “sufficient quantities.”
The toxicity of any substance depends on how much enters the body and over what time period it does so. For example, you probably know that arsenic is a poison, but did you know that you likely have arsenic in your body right now? If you’re a smoker, you have more than a little bit. Same with mercury and cyanide. These substances are in the environment—you can’t avoid them. But they are in such small quantities that they cause no real harm. However, take enough of any of them and they become deadly.
The same can be said for the medications your doctor gives you to treat medical problems. Consider the heart drug digitalis, which comes from the foxglove plant and has been used for over a hundred years to treat heart failure and many types of abnormal heart rhythms. It is also a deadly poison. Too much can lead to nausea, vomiting, and death from dangerous changes in the rhythm of the heart. It’s ironic that it can treat some abnormal heart rhythms while at the same time can cause other more deadly rhythms. It’s all in the dosage. The right dose is medication; the wrong dose is poison.
Toxicology is a marriage of chemistry and physiology, since it deals with chemical substances (chemistry) and how these substances alter or harm living organisms (physiology), particularly humans.
A forensic toxicologist deals with the legal aspects of toxicology. His job is to find and analyze toxic substances in biological materials taken from both the living and the dead, and to determine the physiological, psychological, and behavioral effects on the individual in question. For example, he might be asked to assess the state of inebriation of an automobile accident victim or to determine if someone died from a poison or if the presence of a drug contributed to the victim’s death. This is often more difficult than it sounds.
When the toxicologist investigates a possible poisoning death, he must answer three basic questions:
Was the death due to a poison?
What was the poison used?
Was the intake of the poison accidental, suicidal, or homicidal?
During his analysis, the modern forensic toxicologist sometimes searches for the poison itself, while other times he searches for the poison’s breakdown products. This brings up the concept of biotransformation, which is the conversion or transformation of a chemical into another chemical by the body. We also call this metabolism and the new product produced a metabolite. This process is simply the body destroying or breaking down chemicals and excreting them from the body. This is why you must take most medications each day. The medication is designed to treat some medical problem, and indeed it may do that. But, to the body, the drug is also a foreign toxin and as such must be metabolized and excreted. So, you have to take another dose day after day to keep the blood level of the medication in the therapeutic level.
The metabolism of a drug or toxin typically deactivates the chemical and prepares it for elimination from the body, usually by way of the kidneys. For example, many chemicals are not soluble in water, which means they aren’t soluble in urine, either. The body gets around this by metabolizing (biotransforming) the chemical in such a way that it becomes a new chemical (metabolite) that is water soluble. The metabolite can then be filtered through the kidney, into the urine, and out of the body.
Most metabolites are inactive in that they possess no biological activity and are inert as far as the body is concerned. Other metabolites are active and may have biological properties that are weaker or stronger than the original compound. They may even behave quite differently from the parent compound. For example, cocaine is metabolized into three metabolites: nor-cocaine, which possesses active properties, and benzoylecgonine and methylecgonine, which are inert.
Another example is heroin, which is made from morphine. When heroin is injected into the bloodstream it is immediately converted back into morphine— the chemical that gives the user the “high.”
Since both cocaine and heroin are metabolized to new compounds very quickly, testing for either would be useless. Instead, the toxicologist tests for the presence of cocaine or heroin by searching for their metabolites. Finding them proves that the parent drug was present.
One of the reasons poisoning has been such a popular means for homicide for so many years is that most poisons cause no visible changes in the body, either in the living person or at autopsy. In the days before toxicology labs existed, the poisoner “got away with it” more often than not. After all, if there were no obvious reason for the death, it must have been natural. Since the true cause of death could not be determined, no one could be held responsible.
Of course, some toxins do leave behind visible signs, many of which have been known for years. Corrosive poisons such as acids and lye cause severe damage to the mouth, esophagus, and stomach if they are ingested. Poisonous mushrooms and chlorinated hydrocarbons such a carbon tetrachloride, which for years was used in many carpet cleaners, may cause fatty degeneration of the liver. Cyanide and carbon monoxide cause a cherry-red appearance to the blood and tissues and lead to pinkish lividity. Metallic poisons such as arsenic, mercury, and lead cause characteristic changes in the gastrointestinal tract and the liver.
But this isn’t the norm. Most poisons work their mischief within the cells of the body and leave behind no visible footprints. This means the ME does not often see visible evidence of toxins at autopsy or on the microscopic slides he prepares from the body’s tissues. Instead he collects fluids and tissues from the body and these are analyzed for the presence or absence of toxins by the toxicologist.
Since toxins rarely leave behind visible clues, the ME and the toxicologist must perform specialized tests to reveal their presence. These examinations require various body fluids and tissues, and which ones are used depends on the particular drug in question and the situation under which it is tested. The goal of testing is to establish whether a particular drug is the cause of death, or a contributing factor in the death, or that it played no role at all.
The best places to obtain samples for testing are the locations where the chemicals entered the body, where they concentrate within the body, and along the routes of elimination. This means that blood, stomach contents, and the tissues around injection sites may possess high concentrations of the drug. Analysis of liver, brain, and other tissues may reveal where the drug or its metabolites have accumulated. Finally, urine testing may indicate where the drug and its metabolites are concentrated for final elimination.
During an autopsy, blood, urine, stomach contents, bile, vitreous eye fluid, and tissue samples from the liver, kidneys, muscles, and brain are obtained. If an inhaled toxin is suspected, lung tissue is also taken, and if a chronic heavy metal (arsenic, lead, etc.) poisoning is a consideration, hair samples are taken (the reason is discussed later in this chapter).
It is important that the samples be collected before embalming, since this procedure can interfere with subsequent testing or, as in the case of cyanide, completely destroy the toxin. Also, since embalming fluids may contain methanol and other alcohols, accurate alcohol testing is difficult if not impossible after this procedure.
Let’s look at the most common fluids and tissues obtained by the ME or toxicologist.
BLOOD: Blood is by far the toxicologist’s most useful substance since, with modern toxicological techniques, most drugs and their major metabolites can be found in the blood.
Blood is easily sampled from the living with a simple venipuncture (using a needle to draw blood from a vein, usually in the arm). During an autopsy, blood is typically obtained from several areas. The aorta (the main artery that carries blood out of the heart and to the body), both sides of the heart, and the femoral artery (in the groin area) are common locations. The samples are then placed into glass tubes and sent to the laboratory for testing. If the blood is to be analyzed for volatile chemicals, a sample is placed in a Teflon-lined screw-cap tube. Rubber stoppers should be avoided since they can react with the gases or may also allow them to escape.
The toxicologist not only determines if the toxin is present, but also attempts to assess its level in the body. This is important since low levels may be of no consequence, higher doses may have toxic effects and may have contributed to the person’s actions or played a role in his death, and even higher levels may have been the actual cause of death. Blood is most often the best substance for this assessment.
Concentrations of medicines and drugs within the blood correlate well with levels of intoxication as well as with levels that are potentially lethal. Bioavailability is the amount of the drug that is available for biological activity. Since drugs work on the cellular level, bioavailability means the concentration of the drug that reaches the cells of the body. For most chemicals, the blood level correlates with the cellular level.
For example, the level of alcohol in the blood correlates extremely well with a person’s degree of intoxication, and the lethal level of alcohol in the blood is well known. This knowledge means that the ME can use a blood alcohol level to accurately estimate a person’s degree of intoxication in an automobile accident or whether the fraternity boy died from his binge drinking or from some other cause.
Or let’s say that an individual takes a handful of sedative (sleeping) pills in a suicide attempt. In order for the pills to “work” they must be digested, absorbed into the bloodstream, and carried to the cells of the brain, where the concentration of the drug in the brain cells determines the degree of “poison- ing.” And since the amount of the drug in the blood is an accurate reflection of the amount within the brain cells, testing the blood is like testing the cells.
But, if absorption of the pills from the stomach doesn’t occur, the person will have no effect from the drug. The amount of the drug present in the stomach is irrelevant since it is not available to the brain cells. So, a victim found with undigested pills in his stomach and a very low blood level of the drug did not die from a drug overdose and must have died from something else.
URINE: Easily sampled with a cup and a trip to the restroom, urine testing is a staple of workplace drug testing. It is also useful at autopsy, where it is re- moved by way of a needle inserted into the bladder. Because the kidneys are one of the body’s major drug and toxin elimination routes, toxins are often found in greater concentrations in the urine than in the blood. However, one problem is that the correlation between urine concentration and drug effects in the body is often poor at best. All the urine level can tell the ME is that the drug had been in the blood at some earlier time. It can’t tell him if the drug was exerting any effect on the individual at the time of its collection, or in the case of a corpse, the time of death.
Also, estimating blood concentrations from urine concentrations is impossible. The concentration of any drug in the urine depends on how much urine is produced. If the person has ingested a great deal of water, the urine and any chemicals it contains will be more diluted (watered down) than if the person is “dry.” In addition, alcohol and drugs known as diuretics increase urine volume and decrease the urine concentration of any drugs or metabolites present. Many athletes use diuretics in an attempt to mask or dilute performance-enhancing drugs.
STOMACH CONTENTS: The stomach contents are removed from survivors of drug ingestions by way of a gastric tube, which is typically passed through the nose and into the stomach. The contents are then lavaged (washed) from the stomach and tested for the presence of drugs or poisons.
At autopsy, the stomach contents are similarly tested. Obtaining the stomach contents in any case where poison or drug ingestion is suspected is critical. However, as mentioned earlier, the concentration of any drug in the stomach does not correlate with its blood level and thus its effects on the person. It does, however, show that the drug was ingested and in what quantity.
LIVER: The liver is the center of most drug and toxin metabolism. Testing the liver tissue and the bile it produces can often reveal the drug or its metabolites. Many drugs, particularly opiates, tend to concentrate in the liver and the bile, so they can often be found in these tissues when the blood shows no traces. Where the liver might reflect levels of a drug during the hours before death, the bile may indicate what drugs were in the system over the past three to four days. Neither is very accurate, however.
VITREOUS HUMOR: The vitreous humor is the liquid within the eyeball. It is fairly resistance to putrefaction (decay) and in severely decomposed corpses it may be the only remaining fluid. Testing may uncover the presence of certain drugs.
The vitreous humor is an aqueous (water-like) fluid, which means that chemicals that are water soluble will dissolve in it. It also maintains equilibrium with the blood, so that any water-soluble chemical in the blood will also be found in the vitreous. The important thing is that the level in the vitreous lags behind that of the blood by about one to two hours. This means that test- ing the vitreous will reflect the concentration of the toxin in the blood one to two hours earlier.
HAIR: Hair absorbs certain heavy metal (arsenic, lead, and others) toxins and some other drugs. It has the unique ability to give an intoxication timeline for many of these substances. This will be discussed in greater detail later in this chapter.
INSECTS: In cases where the body is severely decomposed and insects have been feeding on the corpse, the maggots can be tested for drugs. And since some insects tend to concentrate certain drugs in their tissues, they may supply information that the drug was at least present in the victim.
TOXICOLOGY AND THE CAUSE AND MANNER OF DEATH
In the remote past, it was very difficult to determine why someone died, and virtually impossible to ascertain whether a poison was involved. Though modern toxicological techniques have changed things greatly, determining that poisoning was the cause of death remains one of the most difficult tasks facing the forensic toxicologist.
The ultimate responsibility for determining the cause and manner of death lies with the ME or the coroner. To do this he will rely on the circumstances of the death, the crime scene reconstruction, the autopsy findings, and the laboratory results, including the toxicology findings.
In cases where a potentially deadly poison is involved, the toxicologist must uncover the toxin, determine its concentration within the victim, and then give his opinion as to whether this level of this drug was likely lethal. To accomplish this he must consider a number of factors.
The lethal level for many drugs is extremely variable from person to per- son. Age, sex, body size and weight, the presence of other drugs or medications, the state of overall health, and the presence of other diseases impact a given person’s tolerance to some drugs.
For example, a frequent and heavy drinker can tolerate much higher blood alcohol levels than could someone who never drank. A heavy drinker might appear completely sober at a level that would render the normal person unconscious.
Similarly, hardcore heroin addicts routinely inject doses of heroin and attain drug blood levels that would kill the average person in a matter of minutes.
In addition, some drugs are more dangerous to individuals with certain medical problems. The use of amphetamines poses a much greater risk for someone with heart disease or high blood pressure than it would for someone in good health. In this circumstance, a blood level of amphetamines that would not harm the average person could prove lethal for a person with these diseases.
So, it’s not straightforward. When the ME attempts to determine the cause of death in the presence of drugs or toxins, he must consider all these factors. In the absence of other possible causes of death, and with the presence of significant levels of a potentially harmful drug, he might conclude the drug was the proximate cause of death or at least a contributing factor.
Remember that the manners of death are natural, accidental, suicidal, homicidal, and the extra classification of undetermined. Drugs and poisons can be the direct cause or at least a contributing factor in any of these.
NATURAL: A person can die of natural causes even if drugs are involved in the mechanism of death. What if a man with significant coronary artery disease (CAD) took an amphetamine or snorted a few lines of cocaine? Coronary artery disease is a very common disease in which the coronary arteries that supply blood to the heart are plugged with cholesterol plaque.
Amphetamines and cocaine are drugs that increase the heart rate and the blood pressure, both of which increase the need for blood supply to the harder working heart muscle. In addition, these drugs can cause the coronary arteries to spasm (squeeze shut), which greatly decreases the blood supply to the heart muscle. Basically, the supply of blood is reduced at a time when the need is increased, so that the person loses both sides of the supply and demand equation. The victim could suffer a heart attack (actual death of a portion of the heart muscle due to lack of adequate blood supply) or a cardiac arrhythmia (a dangerous change in heart rhythm). Either of these could kill the victim. The cause of death would be a heart attack or a cardiac arrhythmia, events that he would be prone to due to his CAD. But, the amphetamine or cocaine would be a contributory factor. This circumstance is common.
When the ME and the toxicologist confront this situation, they must assess the extent of the victim’s heart disease, the amount of the drug in the body, and whether a heart attack actually occurred. If the amount of drug is low and the victim had severely diseased coronary arteries, they might conclude that the death was natural and that the drug was only a minor contributing factor. On the other hand, if his CAD was mild and the level of drug in his body was high, they might favor an accidental drug death.
But, what if the victim intentionally took a large amount of cocaine, or what if the amphetamines were given to him without his knowledge? The manner of death would then be a suicide or a homicide, respectively. The important point is that the autopsy and lab results would be the same in each circumstance. The ME would need to rely on witness statements and the results of the police investigation to sort this out. And even with this information, the picture might simply be too muddy for the ME to determine the manner of death, and it might be classified as undetermined.
ACCIDENTAL: Most accidental poisonings occur at home and often involve children. Curious by nature, children will eat or drink almost anything: prescription drugs, pesticides, household cleaners, paint thinners, weed killers, snail bait, you name it. In adults, accidental poisoning most often occurs because some product is mislabeled, usually because it has been placed in a container other than its original one. This may be in the form of medications dumped into another bottle, some toxic liquid placed in an empty liquor bottle, or the white powders of cyanide or arsenic stored in a container where they could be confused with sugar or salt.
In other situations, the death might be the result of a dosage miscalculation. Addicts often miscalculate the amount of heroin or amphetamine they are taking and die from this error. The fact that street drugs have poor quality control only adds to this problem. How much heroin is actually in the bag the addict just bought? It may be less or many times more than the bag he purchased yesterday. If the latter is the case and he injects the same dose as he did yesterday, he could easily die from an overdose.
Similarly, some people believe that if one dose of a drug is good, then two must be better. This is a dangerous assumption. Digitalis is a common cardiac medication. Sometimes a patient will decide on his own to double his dose. All is well for a couple of weeks, but as the medicine accumulates within his body, he becomes ill and can die.
Another factor in accidental drug deaths is the mixing of drugs. Alcohol taken with a sedative is notorious for causing death. Addicts often mix cocaine with amphetamines, or heroin with tranquilizers, or just about any combination imaginable, often with tragic results.
SUICIDAL: Drugs are a commonly involved in suicides. Sedatives or sleeping
pills, narcotics, alcohol, and carbon monoxide (see Chapter Eight: Asphyxia, “Toxic Gases”) are commonly used. Often the victim takes multiple drugs, basically whatever is in the medicine cabinet. This presents a difficult problem for the toxicologist. He must analyze the stomach contents, blood, urine, and tissues, and hopefully determine the level of each drug and assess the contribution of each to the victim’s death. He may find that one particularly toxic drug was present in large amounts and that it was the cause of death. Or he might find that a certain combination of drugs was the cause.
The ME uses these findings in conjunction with information from the autopsy and from investigating officers to assess the manner of death. The find- ing of multiple drugs in the victim’s system doesn’t necessarily mean that he took them on purpose. It could have been an accidental overdose driven by the need for relief of physical or psychological pain, or someone else could have surreptitiously slipped the drugs into his food or drink, which would be a homicide.
HOMICIDAL: Though homicidal poisoning was common from antiquity to the twentieth century, it is uncommon today.
As with accidental and suicidal poisonings, homicidal poisonings occur most often at home. This means that the killer must possess knowledge of the victim’s habits and have access to his food, drink, and medications. This knowledge is critical in the homicidal administration of a toxin. It is also important in solving the crime. When the toxicologist determines that the victim was poisoned, the police focus on anyone who had access to the victim.
To dig deeper into this subject grab a copy of either:
FORENSICS FOR DUMMIES: http://www.dplylemd.com/book-details/forensics-for-dummies.html
HOWDUNNIT: FORENSICS: http://www.dplylemd.com/book-details/howdunnit-forensics.html
Criminal Mischief: Episode #25: A Stroll Through Forensic Science History
PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html
FORENSIC SCIENCE TIMELINE
Prehistory: Early cave artists and pot makers “sign” their works with a paint or impressed finger or thumbprint.
1000 b.c.: Chinese use fingerprints to “sign” legal documents.
3rd century BC.: Erasistratus (c. 304–250 b.c.) and Herophilus (c. 335–280 b.c.) perform the first autopsies in Alexandria.
2nd century AD.: Galen (131–200 a.d.), physician to Roman gladiators, dissects both animal and humans to search for the causes of disease.
c. 1000: Roman attorney Quintilian shows that a bloody handprint was intended to frame a blind man for his mother’s murder.
1194: King Richard Plantagenet (1157–1199) officially creates the position of coroner.
1200s: First forensic autopsies are done at the University of Bologna.
1247: Sung Tz’u publishes Hsi Yuan Lu (The Washing Away of Wrongs), the first forensic text.
c. 1348–1350: Pope Clement VI(1291–1352) orders autopsies on victims of the Black Death to hopefully find a cause for the plague.
Late 1400s: Medical schools are established in Padua and Bologna.
1500s: Ambroise Paré (1510–1590) writes extensively on the anatomy of war and homicidal wounds.
1642: University of Leipzig offers the first courses in forensic medicine.
1683: Antony van Leeuwenhoek (1632–1723) employs a microscope to first see living bacteria, which he calls animalcules.
Late 1600s: Giovanni Morgagni (1682–1771) first correlates autopsy findings to various diseases.
1685: Marcello Malpighi first recognizes fingerprint patterns and uses the terms loops and whorls.
1775: Paul Revere recognizes dentures he had made for his friend Dr. Joseph Warren and thus identifies the doctor’s body in a mass grave at Bunker Hill.
1775: Carl Wilhelm Scheele (1742–1786) develops the first test for arsenic.
1784: In what is perhaps the first ballistic comparison, John Toms is convicted of murder based on the match of paper wadding removed from the victim’s wound with paper found in Tom’s pocket.
1787: Johann Metzger develops a method for isolating arsenic.
c. 1800: Franz Joseph Gall (1758–1828) develops the field of phrenology.
1806: Valentine Rose recovers arsenic from a human body.
1813: Mathieu Joseph Bonaventure Orfila (1787–1853) publishes Traité des poisons (Treatise on Poison), the first toxicology textbook.
1821: Sevillas isolates arsenic from human stomach contents and urine, giving birth to the field of forensic toxicology.
1823: Johannes Purkinje (1787–1869) devises the first crude fingerprint classification system.
1835: Henry Goddard (1866–1957) matches two bullets to show they came from the same bullet mould.
1836: Alfred Swaine Taylor (1806–1880) develops first test for arsenic in human tissue.
1836: James Marsh (1794–1846) develops a sensitive test for arsenic (Marsh test).
1853: Ludwig Teichmann (1823–1895) develops the hematin test to test blood for the presence of the characteristic rhomboid crystals.
1858: In Bengal, India, Sir William Herschel (1833–1917) requires natives sign contracts with a hand imprint and shows that fingerprints did not change over a fifty-year period.
1862: Izaak van Deen (1804–1869) develops the guaiac test for blood.
1863: Christian Friedrich Schönbein (1799–1868) develops the hydrogen peroxide test for blood.
1868: Friedrich Miescher (1844–1895) discovers DNA.
1875: Wilhelm Konrad Röntgen (1845–1923) discovers X-rays.
1876: Cesare Lombroso (1835–1909) publishes The Criminal Man, which states that criminals can be identified and classified by their physical characteristics.
1877: Medical examiner system is established in Massachusetts.
1880: Henry Faulds (1843–1930) shows that powder dusting will expose latent fingerprints.
1882: Alphonse Bertillon (1853–1914) develops his anthropometric identification system.
1883: Mark Twain (1835–1910) employs fingerprint identification in his books Life on the Mississippi and The Tragedy of Pudd’nhead Wilson (1893– 1894).
1887: In Sir Arthur Conan Doyle’s first Sherlock Holmes novel, A Study in Scarlet, Holmes develops a chemical to determine whether a stain was blood or not—something that had not yet been done in a real-life investigation.
1889: Alexandre Lacassagne (1843–1924) shows that marks on bullets could be matched to those within a rifled gun barrel.
1892: Sir Francis Galton (1822–1911) publishes his classic textbook Finger Prints.
1892: In Argentina, Juan Vucetich (1858–1925) devises a usable fingerprint classification system.
1892: In Argentina, Francisca Rojas becomes the first person charged with a crime on fingerprint evidence.
1898: Paul Jeserich (1854–1927) uses a microscope for ballistic comparison.
1899: Sir Edward Richard Henry (1850–1931) devises a fingerprint classification system that is the basis for those used in Britain and America today.
1901: Karl Landsteiner (1868–1943) delineates the ABO blood typing system.
1901: Paul Uhlenhuth (1870–1957) devises a method to distinguish between human and animal blood.
1901: Sir Edward Richard Henry becomes head of Scotland Yard and adopts a fingerprint identification system in place of anthropometry.
1902: Harry Jackson becomes the first person in England to be convicted by fingerprint evidence.
1903: Will and William West Case–effectively ended the Bertillion System in favor of fingerprints for identification
1910: Edmund Locard (1877–1966) opens the first forensic laboratory in Lyon, France.
1910: Thomas Jennings becomes the first U.S. citizen convicted of a crime by use of fingerprints.
1915: Leone Lattes (1887–1954) develops a method for ABO typing dried bloodstains.
1920: The Sacco and Vanzetti case brings ballistics to the public’s attention. The case highlights the value of the newly developed comparison microscope.
1923: Los Angeles Police Chief August Vollmer (1876–1955) establishes the first forensic laboratory.
1929: The ballistic analyses used to solve the famous St. Valentine’s Day Massacre in Chicago lead to the establishment of the Scientific Crime Detection Laboratory (SCDL), the first independent crime lab, at Northwestern University.
1932: FBI’s forensic laboratory is established.
1953: James Watson (1928– ), Francis Crick (1916–2004), and Maurice Wilkins (1916–2004) identify DNA’s double-helical structure.
1954: Indiana State Police Captain R.F. Borkenstein develops the breathalyzer.
1971: William Bass establishes the Body Farm at the University of Tennessee in Knoxville.
1974: Detection of gunshot residue by SEM/EDS is developed.
1977: FBI institutes the Automated Fingerprint Identification System (AFIS).
1984: Sir Alec Jeffreys (1950– ) develops the DNA “fingerprint” technique.
1987: In England, Colin Pitchfork becomes the first criminal identified by the use of DNA.
1987: First United States use of DNA for a conviction in the Florida case of Tommy Lee Andrews.
1990: The Combined DNA Index System (CODIS) is established.
1992: The polymerase chain reaction (PCR) technique is introduced.
1994: The DNA analysis of short tandem repeats (STRs) is introduced.
1996: Mitochondrial DNA is first admitted into a U.S. court in Tennessee v. Ware.
1998: The National DNA Index System (NDIS) becomes operational.
Criminal Mischief: Episode #16: Arsenic: An Historical and Modern Poison
PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html
Toxicology is a relatively new science that stands on the shoulders of its predecessors: anatomy, physiology, chemistry, and medicine. Our knowledge in these sciences had to reach a certain level of sophistication before toxicology could become a reality. It slowly evolved over more than two hundred years of testing, starting with tests for arsenic.
Arsenic had been a common poison for centuries, but there was no way to prove that arsenic was the culprit in a suspicious death. Scientist had to isolate and then identify arsenic trioxide—the most common toxic form of arsenic— in the human body before arsenic poisoning became a provable cause of death. The steps that led to a reliable test for arsenic are indicative of how many toxicological procedures developed.
1775: Swedish chemist Carl Wilhelm Scheele (1742–1786) showed that chlorine water would convert arsenic into arsenic acid. He then added metallic zinc and heated the mixture to release arsine gas. When this gas contacted a cold vessel, arsenic would collect on the vessel’s surface.
1787: Johann Metzger (1739–1805) showed that if arsenic were heated with charcoal, a shiny, black “arsenic mirror” would form on the charcoal’s surface.
1806: Valentine Rose discovered that arsenic could be uncovered in the human body. If the stomach contents of victims of arsenic poisoning are treated with potassium carbonate, calcium oxide, and nitric acid, arsenic trioxide results. This could then be tested and confirmed by Metzger’s test.
1813: French chemist Mathieu Joseph Bonaventure Orfila (1787–1853) developed a method for isolating arsenic from dog tissues. He also published the first toxicological text, Traité des poisons (Treatise on Poison), which helped establish toxicology as a true science.
1821: Sevillas used similar techniques to find arsenic in the stomach and urine of individuals who had been poisoned. This is marked as the beginning of the field of forensic toxicology.
1836: Dr. Alfred Swaine Taylor (1806–1880) developed the first test for arsenic in human tissue. He taught chemistry at Grey’s Medical School in England and is credited with establishing the field of forensic toxicology as a medical specialty.
1836: James Marsh (1794–1846) developed an easier and more sensitive version of Metzger’s original test, in which the “arsenic mirror” was collected on a plate of glass or porcelain. The Marsh test became the standard, and its principles were the basis of the more modern method known as the Reinsch test, which we will look at later in this chapter.
As you can see, each step in developing a useful testing procedure for arsenic stands on what discoveries came before. That’s the way science works. Step by step, investigators use what others have discovered to discover even more.
Acute vs. Chronic Poisoning
At times the toxicologist is asked to determine whether a poisoning is acute or chronic. A good example is arsenic, which can kill if given in a single large dose or if given in repeated smaller doses over weeks or months. In either case, the blood level could be high. But the determination of whether the poisoning was acute or chronic may be extremely important. If acute, the suspect list may be long. If chronic, the suspect list would include only those who had long-term contact with the victim, such as a family member, a caretaker, or a family cook.
So, how does the toxicologist make this determination?
In acute arsenic poisoning, the ME would expect to find high levels of arsenic in the stomach and the blood, as well as evidence of corrosion and bleeding in the stomach and intestines, as these are commonly seen in acute arsenic ingestion. If he found little or no arsenic in the stomach and no evidence of acute injury in the gastrointestinal (GI) tract, but high arsenic levels in the blood and tissues, he might suspect that the poisoning was chronic in nature. Here, an analysis of the victim’s hair can be invaluable.
Hair analysis for arsenic (and several other toxins) can reveal exposure to arsenic and also give a timeline of the exposure. The reason this is possible is that arsenic is deposited in the cells of the hair follicles in proportion to the blood level of the arsenic at the time the cell was produced.
In hair growth, the cells of the hair’s follicle undergo change, lose their nuclei, and are incorporated into the growing hair shaft. New follicular cells are produced to replace them and this cycle continues throughout life. Follicular cells produced while the blood levels of arsenic are high contain the poison, and as they are incorporated into the hair shaft the arsenic is, too. On the other hand, any follicular cells that appeared while the arsenic levels were low contain little or no arsenic.
In general, hair grows about a half inch per month. This means that the toxicologist can cut the hair into short segments, measure the arsenic level in each, and reveal a timeline for arsenic exposure in the victim.
Let’s suppose that a wife, who prepares all the family meals, slowly poisoned her husband with arsenic. She began by adding small amounts of the poison to his food in February and continued until his death in July. In May he was hospitalized with gastrointestinal complaints such as nausea, vomiting, and weight loss (all symptoms of arsenic poisoning). No diagnosis was made, but since he was doing better after ten days in the hospital, he was sent home. Such a circumstance is not unusual since these types of gastrointestinal symptoms are common and arsenic poisoning is rare. Physicians rarely think of it and test for it. After returning home, the unfortunate husband once again fell ill and finally died.
As part of the autopsy procedure, the toxicologist might test the victim’s hair for toxins, and if he did, he would find the arsenic. He could then section and test the hair to determine the arsenic level essentially month by month. If the victim’s hair was three inches long, the half inch closest to the scalp would represent July, the next half inch June, the next May, and so on until the last half inch would reflect his exposure to arsenic in February, the month his poisoning began. Arsenic levels are expressed in parts per million (ppm).
An analysis might reveal a pattern like that seen in Figure 11-1.
IMAGE in HOWDUNNIT: FORENSICS
The toxicologist would look at this timeline of exposure and likely determine that the exposure occurred in the victim’s home. The police would then have a few questions for the wife and would likely obtain a search warrant to look for arsenic within the home.
Arsenic Poisoning (2007): CA Poison Control: https://calpoison.org/news/arsenic-poisoning-2007
Arsenic Poisoning Cases Wikipedia: https://en.wikipedia.org/wiki/Arsenic_poisoning_cases
Arsenic” a Murderous History: https://www.dartmouth.edu/~toxmetal/arsenic/history.html
Facts About Arsenic: LiveScience: https://www.livescience.com/29522-arsenic.html
Poison: Who Killed Napolean?: https://www.amnh.org/explore/news-blogs/on-exhibit-posts/poison-what-killed-napoleon
Victorian Poisoners: https://www.historic-uk.com/HistoryUK/HistoryofEngland/Victorian-Poisoners/
12 Female Poisoners Who Killed With Arsenic: http://mentalfloss.com/article/72351/12-female-poisoners-who-killed-arsenic
Criminal Mischief: The Art and Science of Crime Fiction Podcast: https://soundcloud.com/authorsontheair/fentanyl-a-most-dangerous-game
PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html
Fentanyl is a synthetic opioid that is as much as 300 times more powerful than morphine sulfate. It can be injected, ingested, inhaled, and will even penetrate the skin.
It is used in medical situations frequently for pain management, sedation, and for twilight-anesthesia for things such as colonoscopies.
Fentanyl is the number one cause of drug ODs.
Americans have a slightly higher than 1% chance of ultimately dying of an opioid overdose. That’s better than one in 100 people. In fact, 60 people die every day from opioid ODs. That translates to over 22,000 per year. In fact, US life expectancy dropped slightly between 2016 and 2017 due to opioid overdoses.
Thirteen people suffered a mass OD at a party in Chico, Ca in January 2019.
It is often added to other drugs such as heroin to “boost” the heroine effect. Unfortunately, Fentanyl is much more powerful than heroin and when the two are mixed it becomes a deadly combination. It’s also often added to meth and cocaine.
How powerful is fentanyl? A single tablespoon of it could kill as many as 500 people; 120 pounds as many as 25 million people. A recent bust, the largest in US history, recovered over 250 pounds of Fentanyl secreted in a truck crossing the US-Mexico border-—enough to kill 50 million people.
When cops arrest people who possess or are transporting fentanyl they must take precautions not to touch or inhale the product as it could prove fatal. The opioid crises is the reason many cops carry Narcan (Naloxone) with them as either an injection or a nasal spray. It reverses the effects of narcotics very quickly.
The “Dark Web” is a source for many things that can’t be purchased or the open market. Weapons, hitmen, and drugs. But even many of these dealers won’t deal Fentanyl.
Could fentanyl be used as a weapon of terror? Absolutely. A fentanyl aerosol sprayed into a room of people could easily kill everyone present in a matter of minutes. It is a powerful narcotic that acts very quickly and depresses respiration so that people die from asphyxia.
In 2002 a group of around 50 Chechen terrorists who took 850 people hostage in a Moscow theater. Many of the attackers were strapped with explosive vests. The standoff lasted 4 days until the Russians pumped Fentanyl-maybe carfentanil or remifentanil—through the vents and took everyone down. All the terrorists were killed but unfortunately, over 200 of the hostages died before medical help could reach them.
Carfentanil—-Been around since 1974 but just now entering the world of drug abuse. Used in darts as a large animal tranquilizer. AN analog of fentanyl but is 100X stronger.
The famous Kristin Rossum “American Beauty” case involved fentanyl.
Fentanyl Deaths Top Car Accidents: https://www.breitbart.com/politics/2019/01/15/accidental-opioid-deaths-top-car-accident-deaths-for-the-first-time/
Even many “Dark Web” Dealers won’t sell Fentanyl: http://www.newser.com/story/268019/even-dark-web-dealers-refuse-to-sell-this-drug.html
Carfentanil Wikipedia: https://en.wikipedia.org/wiki/Carfentanil
Kristin Rossum Wikipedia: https://en.wikipedia.org/wiki/Kristin_Rossum
Criminal Mischief: The Art and Science of Crime Fiction: Episode 05: Making Characters Compliant
PREVIOUS EPISODES: http://www.dplylemd.com/criminal-mischief.html
Making Characters Compliant Show Notes:
Coercion and Threat
Trauma is time limited
Unconscious vs Pain/Fear of death
Drugs have variable timelines
Drugs don’t have timers
Alcohol and Mickey Finn
Narcotics and sedatives
Date Rape Drugs
E, Ecstasy, MDMA—3.4-Methylenedioxy Methamphetamine
Date Rape Drugs: http://www.dplylemd.com/articles/date-rape-drugs.html
Andrew Luster: https://en.wikipedia.org/wiki/Andrew_Luster
Dr. Grant Robicheaux: http://www.newser.com/story/264806/calif-surgeon-girlfriend-may-have-raped-hundreds.html
Anything can be a poison, it all depends on the dose. This includes the drops you use to clear your eyes.
The active, and dangerous, ingredient in many of these preparations is tetrahydrozoline hydrochloride. If ingested in sufficient amounts, it can elevate the blood pressure, drop the heart rate to dangerously low levels, reduce body temperature, and cause nausea, vomiting, shortness of breath, blurred vision, an unsteady gait, seizures, coma, and death. And you thought those little dropper bottles were harmless.
In a new case, it appears that Lana Clayton killed her husband by adding a few drops to his water over several days. He apparently fell down the stairs. Since this chemical causes walking difficulties, blurred vision, and even seizures, he could easily have staggered and fallen down the steps. Or even been pushed. Regardless, a significant amount of the chemical was found in his blood at autopsy.
I’ve blogged about this before in discussing a case of possible munch Munchausen By Proxy. Samantha Elizabeth Unger apparently poisoned her children by adding a few drops of the medication to their juice on multiple occasions. Here is the link to that post:
GHB is one of the so-called Date Rape Drugs—along with Ecstasy, Rohypnol, and Ketamine. I have an article on these on my website (See Below).
GHB has been difficult to detect, primarily because it’s rapidly metabolized (destroyed) by the body. But new techniques employing Nuclear Magnetic Resonance (NMR) Spectroscopy allow the detection of GHB metabolites (breakdown products) as much as 24 hours later. This gives investigators a longer time period to uncover GHB in a victim.
GHB can also often be found in the victim’s hair up to a month or more after exposure, but this testing is not as yet perfected.
More on the fascinating world of Forensic Toxicology can be found in FORENSICS FOR DUMMIES:
Aconite, also known as monkshood or wolfsbane, is beautiful and looks harmless. Not true. It’s a deadly poison. When ingested, it has potentially deadly cardiotoxic and neurotoxic effects. Its most often kills through the generation of deadly changes in the cardiac rhythm. Victims suffer shortness of breath, palpitations, chest pain, numbness and tingling of the face and other body parts, nausea, and ultimately paralysis, cardiac arrest, and sudden death. Pleasant, huh?
Aconite is easily available, not only at your local nursery but also at various health food stores where it comes in many varieties, including herbal teas. Several recent poisonings related to an aconite-containing herbal tea sold by a San Francisco company show how dangerous this chemical can be. Of course, other health food stores sell aconite and you can easily buy it on the Internet.
I always tell my patients that the second most dangerous place on earth, after a aircraft carrier deck during flight operations, is a health food store. Though most of the products they sell are mostly harmless, and mostly not helpful, some are downright deadly. Many years ago there was a Ma Huang crisis in that several people died from taking supplements laced with this material. Ma Huang is basically an amphetamine and, like aconite can cause deadly cardiac arrhythmias as well as a marked elevation of blood pressure and strokes.
The point is, none of these are regulated. The FDA, for all its warts, does indeed protect consumers. It’s very difficult to create, test, and bring a new drug to market. It cost billions and takes many years, sometimes more than a decade. The FDA requires strict proof that the medicine actually does what it’s designed to do and that its side effects and toxic potential are acceptable and well understood. This is not the case in products you buy at your local health food store. Many are mixed up by a guy named Joe in his garage in a cat box. Trust me, Joe is not a chemist, or a pharmacist, and he possesses no medical training. He might not even have a GED. But he can mix up some cool stuff and put it in fancy packaging and make it look real. And safe. And it might be. But of course, it might not.
The take-home message here is that do not accept the packaging, the product description, or its prime location at eye level on the display rack. Do your research. Find out what’s really inside and what its toxic potential is. And do not buy anything from a guy named Joe.