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Criminal Mischief: Episode #32: Toxicology Part 1

Criminal Mischief: Episode #32: Toxicology Part 1

 

LISTEN: https://soundcloud.com/authorsontheair/episode-32-toxicology-part-1

PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html

SHOW NOTES:

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. 

TOXICOLOGICAL TESTING

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. 

SAMPLE COLLECTION 

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

 

Your Hair and Your ID

 

We’ve known for years that DNA can be obtained from hair and this can be used for identification. If part of the follicle, or bulb, is present, then nuclear DNA can be retrieved and a complete DNA profile can be created. If only the hair shaft is available, then mitochondrial DNA is available and this can help narrow the identity of an individual by showing that the person belongs to a specific maternal line. Not nearly as good as nuclear DNA but this does focus the suspect field to a single maternal line.

But what if the hair shaft could be even more discriminatory? What if it could ID a specific individual and not just someone in the maternal line? Most hair found at crime scenes has been shed naturally and therefore has no follicular material, which might be present if the hair had been yanked free. This means that typically only mitochondrial DNA is available to the crime lab. 

But new studies have found an ultra-sensitive method for determining proteins within the hair shaft itself and it turns out that the types and amounts of the proteins present might be highly specific from individual to individual. This technique obviously is not ready for prime time yet, but it’s something to keep an eye on.

Science Article: https://www.sciencemag.org/news/2019/11/scientists-can-now-identify-someone-single-strand-hair

 

Criminal Mischief on Hiatus Through the Holidays

Criminal Mischief on Hiatus Through the Holidays

 

Criminal Mischief: The Art and Science of Crime Fiction will take a break over the holidays but will be back in January with a three-part series on forensic toxicology. In the meantime, catch up on the 31 past shows:

http://www.dplylemd.com/criminal-mischief.html

Or spend the holidays improving your forensic science knowledge:

 

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 #31: Body Disposal Isn’t Easy

Criminal Mischief: Episode #31: Body Disposal Isn’t Easy

LISTEN: https://soundcloud.com/authorsontheair/episode-31-body-disposal-isnt-easy

PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html

SHOW NOTES: http://www.dplylemd.com/criminal-mischief-notes/31-body-disposal.html

Details/Order: http://www.dplylemd.com/book-details/howdunnit-forensics.html

From HOWDUNNIT:FORENSICS:

GETTING RID OF THE BODY 

Some criminals attempt to destroy corpses, the primary pieces of evidence in homicides. They think that if the police never find the body, they can’t be convicted. This isn’t true, since convictions have in many cases been obtained when no body is found. And destroying a body is no easy task. 

Fire seems to be the favorite tool for this effort. Fortunately, this is essentially never successful. Short of a crematorium, it is nearly impossible to create a fire that burns hot enough or long enough to destroy a human corpse. Cremation uses temperatures of around 1,500oF for two hours or more and still bone fragments and teeth survive. A torched building would rarely reach these temperatures and would not burn for this long. The body inside may be severely charred on the surface, but the inner tissues and internal organs are often very well preserved. 

Another favorite is quicklime. Murderers use this because they have seen it in the movies and because they don’t typically have degrees in chemistry. If they did, they might think twice about this one. Not that quicklime won’t destroy a corpse; it just takes a long time and a lot of the chemical. Most killers who use this method simply dump some on the corpse and bury it, thinking the lime will do its work and nothing will remain. Quicklime is calcium oxide. When it contacts water, as it often does in burial sites, it reacts with the water to make calcium hydroxide, also known as slaked lime. This corrosive material may damage the corpse, but the heat produced from this activity will kill many of the putrefying bacteria and dehydrate the body. This conspires to prevent decay and promote mummification. Thus, the use of quicklime may actually help preserve the body. 

Acids are also used in this regard, and once again the criminal hopes the acid will completely dissolve the body. Serial killer Jeffrey Dahmer tried this with little success. Indeed, powerful acids such as hydrochloric acid (HCl), sulfuric acid (H2SO4), and
chlorosulfuric acid (HClSO3) can destroy a corpse, bones and all. If enough acid is used over a sufficient period of time, that is. But this is not only difficult but also extremely hazardous. The acids will indeed destroy the corpse, but they will also “eat” the tub the body is in and chew up the plumbing. Acid fumes will peel the wallpaper and burn the perpetrator’s skin, eyes, and lungs. 

FORENSIC CASE FILES: THE ACID BATH MURDERER 

John George Haigh came to the English public’s attention in the 1940s when he confessed to not only multiple murders, but also to drinking his victims’ blood and destroying their corpses with acid. He seemed to favor sulfuric acid, which he kept in a vat in his workshop. He took the victims’ money and, through forgery, their property and businesses, and then basically laughed at the police as he admitted to the killings, believing they could not prosecute him without a corpse. He was wrong. He was convicted through forensic evidence and was hanged at Wandsworth Prison on August 10, 1949. 

So, whether it’s Mother Nature or the work of the perpetrator, something almost always remains for the ME and the other forensic scientist to work with. It may be an intact body, a partially destroyed corpse, or a single bone, but it will give them something to use in identification. Let’s take a look at how they do this—first with a body and then with only skeletal remains

BODY LOCATION 

With the exception of some photographic comparisons, all these forensic identification techniques require a corpse or skeletal remains. No body, nothing to work with. Often a discovered body is what instigates this identification process. But sometimes, investigators know a homicide has occurred, or has likely occurred, but they can’t find the corpse. The Laci Peterson case is an example. When Laci, who was eight months pregnant at the time, went missing on Christmas Eve 2002, in Modesto, California, it was not long before it became obvious that she had been murdered. Authorities launched a search of her neighborhood and the bay where her husband, Scott, had been fishing. In April 2003, the bodies of Laci and her unborn son Conner washed up on shore in San Francisco Bay. Scott Peterson was later convicted of the double murder. 

In homicides, finding and examining the corpse is critical. Searchers use a number of low- and high-tech location methods. All evidence is used to narrow the search area, including the victim’s work and leisure habits and witness statements. The victim may work several miles from home, so searching along this route would be undertaken. Maybe he frequently ran or walked in a nearby wooded area. Or maybe the suspect’s vehicle was spotted or some of the victim’s clothing was found in a remote area. These bits of information can greatly focus the search. 

One basic rule is to “look downhill” for a burial site. Let’s say it is believed that the body in question was buried near a remote roadway. In the area, the terrain rises above the road on one side and falls away on the other. Search downhill. Why? It is much easier to carry a body downhill than up. It’s just that simple. 

Once the area of search has been defined, a systematic approach to cover- ing the area should be followed. Freshly turned dirt, trenches, elevations or depressions in the terrain may be helpful. Fresh graves tend to be elevated above the surrounding area, while older ones may be depressed. This is due to settling of the soil, decay of the body, and collapse of the skeleton. Interestingly, the depth of the depression is greater if the body is deeply buried. This is likely due to the larger amount of turned dirt, which is subject to a greater degree of settling. Another factor could be that in deeper graves, the increased weight of the dirt over the corpse causes earlier and more complete skeletal collapse. 

Tracking dogs, if provided with an article of the victim’s clothing, may be able to follow a scent trail to the burial site. Specially trained cadaver dogs search for the scent of decaying flesh. They can often locate bodies in shallow graves or in water. Deeper graves may present problems.

Another important clue may come from changes in the vegetation over the gravesite. The turning of the soil in the digging process and the presence of the body change the soil conditions in the area over the grave. Changes in compaction, moisture, aeration, and temperature may attract plant species that differ from those around the grave. Or, the plants typical for the area may be present but the changed soil conditions may increase the thickness and richness of their growth. This may be visible, particularly from the air. 

Aerial reconnaissance and photography can be coupled with thermal imaging. Freshly turned dirt loses heat faster than normally compacted soil; it appears “colder” by such a device. Alternatively, a decaying body releases heat, which may reveal a measurable difference when compared to the surrounding area. So, the thermal images are inspected for either cold or warm spots, and these areas are then subjected to a more aggressive search. 

If a suspect area such as a mound or depression is found, special devices that locate sources of heat and nitrogen, both byproducts of the decay process, or that measure changes in the physical properties of the soil, may be employed. Ground-penetrating radar can “see” into the ground and often locate a buried body. Measurement of the electrical conductivity may prove helpful— a buried body often adds moisture to the soil, and the moisture increases the soil’s electrical conductivity. Two metal probes are placed in the soil, and an electrical current is passed between them and measured. Changes in this current may indicate where the body is buried. 

Magnetic devices may also be employed. A simple metal detector may locate the victim’s jewelry or belt buckle. 

A special device called a magnetometer, which measures the magnetic properties of soil, can also be helpful. Soil contains small amounts of iron, so it possesses a low level of magnetic reaction. Since the area where the body is buried has proportionally less soil (the corpse takes up space), it will exhibit a lower level of magnetic reactivity. The magnetometer is passed above the soil and locates any areas that have low magnetic reactivity. 

Body Encased in Concrete: https://www.breitbart.com/crime/2019/10/17/police-find-missing-womans-body-encased-concrete-arrest-two-suspects/

Body in Concrete in Plastic Storage Container: http://usnews.nbcnews.com/_news/2012/10/13/14409189-murder-victim-found-entombed-in-concrete-was-former-fla-journalist

Acid in Tub: https://www.independent.co.uk/news/world/europe/french-students-dissolve-body-in-acid-after-killing-girl-in-breaking-bad-murder-plot-10447943.html

Body Beneath Another Corpse: https://www.newser.com/story/240700/husband-hid-wifes-body-under-grave-of-wwii-veteran.html

Body Parts in Trash Bags: https://6abc.com/archive/6880388/

Cooked Spouse: https://latimesblogs.latimes.com/lanow/2012/09/la-chef-told-police-he-slow-cooked-his-wife-for-days.html

Laci Petersen in the San Francisco Bay: https://en.wikipedia.org/wiki/Scott_Peterson

Corpse in Freezer in Truck: https://www.latimes.com/archives/la-xpm-1994-07-18-mn-17076-story.html

And

https://murderpedia.org/male.F/f/famalaro-john.htm

The Science of Finding Buried Bodies: http://theconversation.com/the-science-of-finding-buried-bodies-77803

The Science of Finding Dead Bodies: https://www.dailymail.co.uk/sciencetech/article-4515430/Researchers-reveal-track-corpse.html

 

Criminal Mischief: Episode #27: ABO Blood Typing

Criminal Mischief: Episode #27: ABO Blood Typing

 

LISTEN: https://soundcloud.com/authorsontheair/27-abo-blood-typing

PAST SHOWS: http://www.dplylemd.com/criminal-mischief.html

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ABO Blood Type System

From FORENSICS FOR DUMMIES

By simply typing the blood at a crime scene, investigators narrow their suspect list and completely exonerate some suspects by using the population distribution information for the four ABO blood types. 

Population Distribution of ABO Blood Types

O: 43%

A: 42%

B: 12%

AB: 3%

Besides determining the ABO type, serologists are able to further individualize blood samples. RBCs contain more proteins, enzymes, and antigens than those used in the ABO classification system. These include antigens with such catchy names as Duffy, Kell, and Kidd and intracellular enzymes such as adenylate kinase, erythrocyte acid phosphatase, and the very useful phosphoglucomutase (PGM).

PGM is an enzyme that appears in many different forms, or isoenzymes, and at least ten of them are fairly common. Regardless of ABO type, a particular individual can have any combination of the isoenzymes of PGM. The ME and the serologist use that fact to further narrow the list of suspects for further DNA analyses and confirmation that they were capable of leaving a particular bloodstain.

For example, say that a stain is Type AB and has PGM 2. The ME knows the AB blood type is found in only 3 percent (see Table 14‐1) of the population, and PGM 2 is found in only 6 percent of people. Because these two factors are inherited independently, the probability of a particular individual being Type AB, PGM 2 is only 0.18 percent or less than 2 per 1,000. 

If the police find blood at the scene that matches the blood of a suspect who has Type AB, PGM 2 blood, the probability that that suspect is not the perpetrator is 2 in 1,000. Although not perfect, those odds still are much better than a coin toss. 

Testing for Paternity 

You inherit your blood type from your parents. For that reason, a serologist can assess paternity in many cases. The crime lab is often involved in paternity testing because paternity may be a critical component in determining child support, custody, and visitation. It also may play an important role in crimes and civil proceedings that involve kidnappings, insurance fraud, and inheritance conflicts. 

Inheriting your blood type 

ABO blood types, or phenotypes, come in only four varieties: A, B, AB, and O. But, for some blood types two genotypes, or gene pairings, are possible. A phenotype is what something looks like (in this case the ABO blood type), while the genotype is the underlying genetic pattern. We receive our ABO genes from our parents, one from Dad and one from Mom. 

The important thing to know in this system is that A and B genes are co-dominant (equally dominant), while the O gene is recessive. So someone who receives an A gene from one parent and an O gene from the other has Type A blood, but not Type O, because the A gene is dominant. 

Determining Possible Genotypes from Phenotypes 

Type A: AA or AO

Type B: BB or BO

Type AB: AB

Type O: OO

People with Type O blood must have an OO genotype. They can have neither an A nor a B gene because having one or the other dominates the O gene and produces either Type A or Type B blood. 

A person with Type A blood can either receive an A gene from each parent and thus have an AA genotype or an A gene from one parent and an O gene from the other for an AO genotype. Remember, A is dominant, so when it is paired with the recessive O gene, the A gene determines blood type. People with the AA and AO genotypes both have Type A blood, but genetically speaking, they’re different. 

Type A parents who have AA genotypes can provide only A genes to their offspring, because all their eggs or sperm have an A gene. But Type A parents who have AO genotypes can provide either an A gene or an O gene to their offspring, because half their eggs or sperm have an A gene, and the other half have an O gene. When both parents are Type A, several possibilities exist for the genotype their offspring will have.

In each of the scenarios presented in Figure 14‐1, the child’s blood type is Type A, except when both parents donate an O gene. In the latter case, the child’s genotype and blood type (phenotype) respectively are OO and Type O. These parents can’t have any offspring who have Type B phenotype or BB, BO, or AB genotypes, because neither parent has a B gene to donate. 

Determining Fatherhood

Blood typing can exclude paternity but cannot absolutely verify it. For example, a man with Type AB blood can’t father a child with Type O blood. So if a child has Type O blood, all men with the Type AB are ruled out as the child’s father. A man with Type A (genotypes AA or AO) blood can be the father, but only if he has an AO genotype. Men who have AA genotypes also are excluded. Men with the AO genotype, however, can’t be ruled out at this point. 

To dig deeper into this complex system 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

 

Criminal Mischief: Episode #25: A Stroll Through Forensic Science History

 

 

LISTEN:https://soundcloud.com/authorsontheair/forensicsciencehistory

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SHOW NOTES: http://www.dplylemd.com/criminal-mischief-notes/25-a-stroll-through-forensi.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.

Since then:

Touch DNA

Familial DNA

Phenotypic DNA

 

Talking About Forensic Science on the For Dummies Podcast Series

 

Had I a great time chatting with Eric Martsolf on the For Dummies podcast series about FORENSICS FOR DUMMIES and Forensic Science. Drop by and take a listen:

http://fordummiesthepodcast.twa.libsynpro.com/for-dummies-the-podcast-forensics

More Info and to order FORENSICS FRO DUMMIES:
http://www.dplylemd.com/book-details/forensics-for-dummies.html

 

 

 

 
 
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