Category Archives: General Forensics

When Researching Forensics, Remember to:


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So you do all that forensic science research for your story and find a bunch of cool stuff. Now what? How do you use it to make your story believable, and convoluted, and of course suspenseful.

Here is a post I wrote for Le Coeur de l’Artiste that might help.

Original post is here:

When Researching Forensics, Remember to:

Make the Time of Death Vague: When your disheveled detective is standing over the body and chatting with the coroner and the subject of the time of death comes up, don’t have your coroner/medical examiner say something stupid like, “The victim died at 10:30 last night.” There is no way he could know this. The things he uses to determine the time of death during the first 48 hours – – things like body temperature, rigor mortis, and lividity – – aren’t very accurate. They are merely suggestions. But by using these techniques, the coroner can at least make an educated guess as to the APPROXIMATE time of death. And it is always a best guess. Realistically he should say something like, “The victim died somewhere between 10 PM and midnight.” And that gives you wiggle room in your plot.

Give Your Crime Lab Time to Breathe: Only on television do crime labs get results before the first commercial break. You know, the DNA sample is obtained and three minutes later they have the results, complete with a holographic image of the bad guy. Unfortunately, that is humorously far from reality. DNA analysis, toxicological testing, and most other forensic science techniques take time. The tests not only have to be done, they have to be checked and rechecked, and in high-profile cases, they are often sent out to other labs for corroboration. This takes time. At least days, and often weeks. Remember to allow for this when you’re plotting your story as this delay can add tension.

Make the Evidence Difficult to Find or Not Useful: The truth is that evidence is not always present. Of course, the crime scene technicians look for fingerprints, bodily fluids, shoe impressions, hair and fiber, and any other bits of evidence the perpetrator might have deposited at the crime scene. These might or might not be present, and if present might or might not be found, and if found might or might not be useful. If fingerprints are deposited on a window pane, a tile countertop, or some other smooth, hard surface, then they are often easily found and are clear and useful. If they are on a rough surface, such as a wooden slat or concrete, or if they are smeared or contaminated or altered in some way, they might not be useful. The pattern might be disrupted or difficult to see and if so the print is useless. DNA might be found but it might be so damaged from decay or contamination that it is not useful. So make it difficult for your detective. Don’t make the evidence jump right into his lap.

Make Everyone Involved in the Investigation Honest and Capable, or Not: The best-selling horror writer John Saul has said that he places his stories in small towns because the cops are stupid. This might be true in many cases, but I think what John means is that they are not sophisticated, experienced, or well-equipped to handle many criminal situations. This might be because they are poorly trained, or never worked in a major city, or solved any major crimes and therefore a murder in their small town might be beyond their capabilities. Or perhaps the city’s budget for crime-fighting is so small that they can’t afford to hire experienced officers, or forensic experts, or even do autopsies. It might be that those in power are just flat out criminally corrupt, or lazy, or incompetent. If your story is set in a major city, such as Los Angeles, New York, Houston, or Miami, then sophisticated crime-fighting techniques, equipment, labs, and experts are easily available. But if it’s set in a small town, none of these are available. Use this to add tension to your story.

Make the Evidence Controversial: Just because a certain individual’s fingerprints or DNA or shoe impressions are left at the crime scene, it does not mean that person is the perpetrator of the crime. The thing about evidence is that it creates linkage. It links a person, an object, or a place to another person, object, or place. That is, if Joe’s fingerprints are found at the scene of the crime it means that at some point in time Joe was at that location. It does not mean Joe is the one that killed Martha. This is why when police begin their interrogation of Joe they will first ask him if he has been in Martha’s home, or if he even knows Martha. If he says yes, he knows her well and has been in her home many times, then there may be a perfectly innocent reason for his fingerprints to be there. If he says no that he does not know her and has never been in her home, then Joe has some explaining to do. Such evidence that points in the wrong direction is very useful for creating classic red herrings in your story.

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Crime and Science Radio: Crime Scenes, Criminalistics, and the Cutting Edge

Crime and Science Radio: Crime Scenes, Criminalistics, and the Cutting Edge in Los Angeles: An Interview with Former LASD Criminalist Professor Donald Johnson of California State University, Los Angeles

BIO: Professor Donald James Johnson is an expert on criminalistics, with emphasis on crime scene investigation and reconstruction (homicides and sexual assaults), and forensic biology. His research interests include the application of new technologies to the field of criminalistics. He was formerly a senior criminalist at the Los Angeles County Sheriff’s Department, where he was involved in the scientific investigation of violent crimes.

NOTE: This show was recorded live at the MWA-LA Chapter meeting in Los Angels, CA


Link will go live Saturday 9-10-16 at 10 a.m. Pacific


California Forensic Science Institute:

School of Criminal Justice and Criminalistics at CSULA:

CSULA Masters in Criminalistics

Los Angeles County Sheriff’s Department Scientific Services video:

Los Angeles County Sheriff’s Department:

American Academy of Forensic Sciences


Q&A: Will a Decaying Corpse Actually Produce Alcohol?

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Q: Is it possible or likely for blood alcohol levels to increase or decrease in a decomposing body, and if so during what stages of decomposition?

A: Alcohol is usually consumed in the decay process but may actually be produced and this might cloud any toxicological examinations on the corpse. Make it look as if the victim consumed more alcohol than he actually did.

I must point out that alcohol is not commonly produced but it does happen in rare cases. The alcohol is a byproduct of the action of some types of bacteria that are involved in the decay process. This means that alcohol can only appear during active decay. What is that time period? A little about putrefaction.

The decomposition of the human body involves two distinct processes: autolysis and putrefaction. Autolysis is basically a process of self-digestion. After death, the enzymes within the body’s cells begin the chemical breakdown of the cells and tissues. As with most chemical reactions the process is hastened by heat and slowed by cold. Putrefaction is the bacterially mediated destruction of the body’s tissues. It is this decay that might cause some alcohol formation. Not always, but sometimes. The responsible bacteria mostly come for the intestinal tract of the deceased, though environmental bacteria and yeasts contribute in many situations. Bacteria thrive in warm, moist environments and become sluggish in colder climes. Freezing will stop their activities completely. A frozen body will not undergo putrefaction until it thaws.

Under normal temperate conditions, putrefaction follows a known sequence. During the first 24 hours, the abdomen takes on a greenish discoloration, which spreads to the neck, shoulders, and head. Bloating follows. This is due to the accumulation of gas, a byproduct of the action of bacteria, within the body’s cavities and skin. This swelling begins in the face where the features swell and the eyes and tongue protrude. The skin will then begin to “marble.” This is a web-like pattern of the blood vessels over the face, chest, abdomen, and extremities. This pattern is green-black in color and is due to the reaction of the blood’s hemoglobin with hydrogen sulfide. As gasses continue to accumulate, the abdomen swells and the skin begins to blister. Soon, skin and hair slippage occur and the fingernails begin to slough off. By this stage, the body has taken on a greenish-black color. The fluids of decomposition (purge fluid) will begin to drain from nose and mouth. This may look like bleeding from trauma, but is due to extensive breakdown of the body’s tissues.

The rate at which this process occurs is almost never “normal” because conditions surrounding the body are almost never “normal.” Both environmental and internal body conditions alter this process greatly. Obesity, excess clothing, a hot and humid environment, and the presence of sepsis may speed this process so that 24 hours appear like 5 or 6 days have passed. Sepsis is particularly destructive to the body. Not only would the body temperature be higher at death, but also the septic process would have spread bacteria throughout the body. In this case, the decay process would begin quickly and in a widespread fashion. A septic body that is dead for only a few hours may appear as if it has been dead for several days.

As opposed to the above situations, a thin, unclothed corpse lying on a cold surface with a cool breeze would follow a much slower decomposition process. Very cold climes may slow the process so much that even after several months, the body appears as if it has been dead only a day or two. Freezing will protect the body from putrefaction if the body is frozen before the process begins. Once putrefaction sets in, even freezing the body may not prevent its eventual decay. If frozen quickly enough, the body may be preserved for years.

So, whether a particular corpse actually produces alcohol or not is totally unpredictable. How long it takes depends upon the conditions the corpse is exposed to. In a corpse in an enclosed garage in Houston in August, this process will be very rapid and the corpse will be severely decayed after 48 hours. If parked in a snow bank in Minnesota in February it might not even begin the decay process until April or May when the spring thaw occurs. And anything in between. The appearance of any alcohol would coincide with the time frame of the bacterial activity.

So how does the ME get around this possibility? How can he determine the actual alcohol level that was present prior to the decay process kicking in? He can’t with any absolute accuracy, but he does have a tool that will help him make a best guess. He can extract the vitreous humor from the victim’s eye—this is the jelly-like fluid that fills the eyeballs. The alcohol level within this fluid matches that of the blood with about a two-hour delay. That is, the level within the vitreous at any given time reflects the blood alcohol level that was present approximately two hours earlier. And the vitreous is slow to decay so it might be intact even though the corpse is severely decayed. By measuring the vitreous level the ME will know the blood alcohol level two hours prior to death and he can then estimate the blood alcohol level at the time of death.


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This question originally appeared in MORE FORENSICS AND FICTION


Crime and Science Radio: The BTK Killer and Other Serial Murderers: An Interview with Psychologist and Author Dr. Katherine Ramsland

This Saturday at 10 a.m. Pacific Jan Burke and I welcome Dr. Katherine Ramsland to the show to discuss her years of research into one of America’s most notorious serial killers Dennis Rader, the BTK Killer and her wonderful book that has resulted form this work.



Dr. Katherine Ramsland


BIO: Dr. Katherine Ramsland, director of the Master of Arts in Criminal Justice program at DeSales University, also teaches the forensic psychology track. She has published over 1,000 articles, stories, and reviews, and 59 books, including The Mind of a Murderer, The Forensic Science of CSI, Inside the Minds of Serial Killers, The Human Predator: A Historical Chronicle of Serial Murder and Forensic Investigation, The Ivy League Killer, and The Murder Game. Her book, Psychopath, was a #1 bestseller on the Wall Street Journal’s list. With former FBI profiler Gregg McCrary, she co-authored a book on his cases, The Unknown Darkness: Profiling the Predators among Us, with Dr. Henry C. Lee, The Real Life of a Forensic Scientist, and with Professor James E. Starrs, A Voice for the Dead. She presents workshops to law enforcement, psychologists, coroners, judges, and attorneys, and has consulted for several television series, including CSI and Bones She also writes a regular blog for Psychology Today called “Shadow-boxing” and consults for numerous crime documentary production companies. Her most recent book (August 2016) is with serial killer, Dennis Rader, called Confessions of a Serial Killer: The Untold Story of Dennis Rader, the BTK Killer. She will also publish The Ripper Letter, a supernatural thriller based on Jack the Ripper lore, and a textbook, Forensic Investigation: Methods from Experts (2017).


Link goes live Saturday August 13, 2016 at 10 a.m. Pacific




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Crime and Science Radio Goes Live at MWA-LA

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Mark your calendars for this event. Jan and I are recording an episode of Crime and Science Radio live with our special guest Criminalist and Forensic Science Professor Don Johnson. This will be a fun and informative event. Sign up now.


We have a special luncheon planned in August:

D.P. Lyle and Jan Burke Live Radio Podcast with special guest interviewee Criminalist and Forensics Professor Don Johnson

This will be a unique opportunity to experience a live podcast with three outstanding experts

Sunday, August 7, 2016

Tam O’Shanter Restaurant

2980 Los Feliz Blvd.

Los Angeles

Doors open at 11:30



Q&A: What Injuries Can Occur With a Car Bomb?

Q&A: What Injuries Can Occur With a Car Bomb?

Q: How far away would you have to be from a car bomb (the kind that is detonated by starting the car) to survive with injuries and what sorts of injuries might you sustain in the blast?

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A: This is a question that is virtually impossible to answer with any degree of accuracy. There are entirely too many variables involved. How big is the bomb? How big is the car? How close is close? What direction does the shrapnel fly and in which direction is the concussive force of the bomb directed? Are there any intervening walls or structures that might dampen the concussive force or block or redirect the shrapnel? Each of these variables, and many others, must be taken into account before any prediction of possible injuries can be entertained.

Lets look at a few general principles however. Big bombs cause big problems and little bombs cause less. A large bomb can produce a massive concussive force that will spread out for many yards in every direction. It can also produce shrapnel that can fly many hundreds of feet. A small bomb, needless to say, would release a smaller concussive force and any shrapnel would move at a slower rate and therefore do less damage.

Let’s assume that this is a moderate sized bomb and the victim is standing close enough to receive injuries from the explosion. There are several types of injuries that can occur with a bomb.

If the person is close enough and the bomb is of the type that produces a great deal of heat, then burns over the skin and face can occur and even the victim’s clothing might catch fire. This could produce severe injury to the flesh and the lungs.

The concussive force of the bomb is simply a wave of air molecules that are accelerated to very high speed. When the wave strikes an object or a person, damage and bodily trauma will result. This is why a bomb will destroy a building, knock down a wall, or kill a person within the concussive umbrella. If the force is strong enough it can burst eardrums, cause sinuses within the nose and face to bleed, rupture the lungs, rupture the abdomen and internal organs, and many other nasty injuries. If the person is slightly further away, or if the concussive force is dampened somewhat, then injuries to the eardrums and sinuses may occur but the other more severe injuries to the lungs and internal organs might not occur.

Shrapnel presents a very difficult and dangerous situation. With a car exploding all types of shrapnel can be fired in every direction. Chunks of metal and glass, complete doors or windows, beams of metal and even the engine can be launched in any direction. The types of injuries that someone would suffer depends upon exactly what strikes them, where they are struck, and with what speed and force they are hit. I think it would be obvious that if a car door or engine or some large piece of metal struck someone at very high velocity it would most likely kill them instantly and if not their injuries would be so severe that without very aggressive medical treatment and luck they would die from these in short order. But what about smaller pieces of glass and metal? These can penetrate the head, the chest, or the abdomen and damage vital organs and lead to death very quickly. Or they can enter the same areas and lead to massive injury and bleeding, which can then lead to death in minutes to an hour or so. Or they could simply be flesh wounds and the person could survive but would likely require surgical repair of the wounds and treatment with antibiotics to prevent secondary infections.

You can see almost anything can happen in this explosive situation.  A large explosion at a great distance could easily do the same damage as a smaller one where the person was standing close by. Any bomb where the concussive force and shrapnel were directed away from the person might produce no injuries while if the victim were standing in the path of the concussive wave and the shrapnel he could be killed instantly. And anywhere in between. This great degree of variation in what actually happens is good for storytelling since it means that you can craft your story almost any way you want.


Can a DNA Sample Reveal Age?


DNA found at crime scenes can be extremely useful in identifying a perpetrator. But this only works if they have a known suspect and a DNA sample from that suspect, or if the perpetrator is in the national DNA database—-CODIS. Without something to compare the crime scene DNA sample against, DNA is not very useful. Same can be said for fingerprints. But perhaps DNA offers something else.

Employing DNA obtained from a crime scene, Familial DNA has been used to narrow the list of potential suspects and this has proven useful in many cases—such as the famous Grim Sleeper serial killer. I have blogged on this before in cases such as The Boston Strangler and the amazing case of Yara Gambirasio.

DNA will of course reveal gender, but there is also research suggesting that race, hair and eye color, and physical features such as stature might also be determined from a DNA sample. These aren’t completely worked out yet but they are intriguing aspects of DNA analysis.

But what if a DNA sample could be used to determine the approximate age of the person? This would definitely help as, once again, it would narrow the suspect list. For example, if the crime scene DNA could be shown to have come from someone who was approximately 25 years old it would effectively eliminate a 60-year-old suspect. But is this possible? Maybe.

A new approach, using a process of gene expression called methylation, seems to offer hope. Researchers at the KU Leuven University in Belgium have developed a technique for assessing the degree of methylation in a DNA sample. They believe that this analysis will narrow the age range of the individual down to a four or five year window. If this proves to be true, law enforcement will have another useful forensic science tool.

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