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Category Archives: General Forensics

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?

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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.

 

Guest Blogger: Lisa Black: Everything Old Is New Again

EVERYTHING OLD IS NEW AGAIN

My character, Cleveland forensic specialist Maggie Gardner, is unrealistic in one respect—she still spends a lot of time at her microscope looking at tiny bits of trace evidence, hairs, fibers, paint, and glass.

No one does that any more. Well, maybe Abby on NCIS, but she’s the most unrealistic forensic person on screen, even though she’s so cute we don’t care.

Sure, on old episodes of Dragnet you can see some nerdy guy in a lab coat explain how these pollen spores are only found in one quadrant of the city, but that art had already died before I started in forensics in 1994. We got spoiled by DNA, by ‘absolutely yes’ or ‘absolutely no’ answers. No one wanted to hear that this red nylon was ‘consistent with’ the suspect’s shirt, because they wouldn’t be hearing how many red nylon shirts were manufactured, how many were sold in this area, and while we’re at it let’s hack into Macy’s sales figures and find out who they were sold to. Unlike television, forensic labs do not have databases of all this information and would probably be violating a few important laws if they did. Nope, ‘consistent with’ was all you got. Take it or leave it.

 

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POLYURETHANE FIBERS

They left it. Microscopic analysis became more or less a thing of the past. Forensic techs today wouldn’t recognize a pollen spore or know what to do with it if they did. Fibers are ignored. Hairs are examined only to screen out candidates for, well, DNA.

Imagine my surprise, then, when I peruse the latest Journal of Forensic Sciences and stumble on an article about using something called palynological scanning to rapidly evaluate suspect and victim testimony.

 

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POLLEN

Palynology, it turns out, is a fancy name for…pollen. Pollen and spores and other ‘microscopic entities’ of trees, shrubs and herbs. No hairs, fibers or paint, but you get the idea. This analysis proved useful in some cases of rape or assault, in situations where the victim and suspect both contacted the ground and pieces of the ambient flora could attach to their clothing.

 

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In one case the suspect said he and his victim engaged on a lawn behind a public building. The victim said he attacked in a heavily wooded area, the spot surrounded by beech, birch and sycamore trees. Each site had a distinct mix of items—palynomorphs– with complicated Latin names. The suspect didn’t deny that he had made contact with the victim so willingly gave up the clothing he’d been wearing at the time, and sure enough, all those little palynomorphs indicated that he had been in the woods and not on the lawn. This did not prove that he had committed the crime. It only proved that he had lied about the sequence of events, and that was sufficient to prompt a confession. Otherwise this case would have languished in an eternal hell of ‘he said vs. she said.’

Of course had this guy listened to legal counsel before he made a statement, he probably would have figured out to come up with an alternative, and innocent, reason to have been rolling on the ground near the crime scene, and all these spores would have been for naught. As it is, surely the defense will bring out statistics regarding the vast number of beech and sycamore trees in the area, perhaps in the suspect’s own neighborhood, and the idea that maybe he had been doing some gardening earlier in the week in that same pair of pants. This is why things like pollen analysis fell out of favor with the courts…but the spores are still out there, voluminous, distinct and quite concrete little buggers that will stick in all sorts of places one might wish they wouldn’t. So are hairs, fibers, and paint. Maybe ‘consistent with’ is all you can get out of them. But maybe, sometimes, that’s enough.

So in my books Maggie still looks at all this stuff because it’s more visible and visceral than yet one more DNA sample. Let’s face it—you’ve seen one cotton swab, you’ve seen them all. Bright clothing fibers are much more entertaining.

And this trace evidence will lead her down a number of roads—some of which, it turns out, she’d be better off avoiding.

Wiltshire et al. “A Rapid and Efficient Method for Evaluation of Suspect Testimony: Palynological Screening.” Journal of Forensic Sciences, Vol. 60, #6, Nov 2015, pp 1441-1450.

 

L Black

Lisa Black has spent over 20 years in forensic science, first at the coroner’s office in Cleveland Ohio and now as a certified latent print examiner and CSI at a Florida police dept. Her books have been translated into 6 languages, one reached the NYT Bestseller’s List and one has been optioned for film and a possible TV series.

Lisa’s Website: http://www.lisa-black.com

 

that darkness cover

 

Hello! Just a quick note to let you know that my new book, That Darkness, is now available wherever books are sold!

It seemed like a typical week for crime scene specialist Maggie Gardiner–a gang boss shot in an alley, a lost girl draped over an ancient grave, a human trafficker dumped in the river–nothing all that out of the ordinary for the Cleveland police department as spring turns toward summer along the Erie banks. The methods are usual, the victims unsurprising–but when she notices a pattern, a tenuous similarity among the cases, she begins to realize that her days will never be typical again. How much of her life, her career, her friends, will she be willing to risk to do what’s right?

Jack Renner is a killer who does not kill for any of the conventional reasons…no mania, no personal demons. He simply wants to make the world a safer place. He doesn’t think of himself as a dangerous person–but he can’t let anyone stop him. Not even someone as well-meaning as Maggie Gardiner.

Maggie has the self-sufficiency of a born bit-of-a-loner. She works with a bevy of clever experts surrounded by armed police officers. She is both street smart and book smart, having seen the worst the city has to offer.

But Maggie Gardiner is not safe. And, until she can draw Jack Renner into the light, neither is anyone else.

Jeff Lindsay, author of the Dexter series, says: “Lisa Black always delivers authentic characters in riveting stories. That Darkness takes things to a spellbinding new level with a taut and haunting story that will stay with you long after you finish reading it.”

Publisher’s Weekly says: “The intriguing forensic details help drive the plot to its satisfying conclusion.”

“Black is one of the best writers of the world of forensics, and her latest introduces Maggie Gardiner, who works for the Cleveland Police Department. Her relentless pursuit of answers in a dark world of violence is both inspiring and riveting. Readers who enjoy insight into a world from an expert in the field should look no further than Black. Although Cornwell is better known, Black deserves more attention for her skillful writing – and hopefully this will be her breakout book.”– RT Book Reviews, 4 Stars (Top Pick)

 

Crime and Science Radio: Research, Education, and the Future of Forensic Science: an Interview with Dr. Katherine A. Roberts, Director of the CSULA Graduate Program in Criminalistics

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Research, Education, and the Future of Forensic Science: an Interview with Dr. Katherine A. Roberts, Director of the CSULA Graduate Program in Criminalistics

 

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BIO: Dr. Roberts is the Director of the California State University, Los Angeles Graduate Program in Criminalistics. She has served as the Director of the Master of Science degree program there since 2002,and played a leading role in the university’s FEPAC accreditation. Her research interests cover a wide array of forensic disciplines, but focus primarily of trace evidence analysis, sexual assault evidence, and mitochondrial DNA analysis. Dr. Roberts was the PI of a National Institute of Justice-funded study to investigate the use of samplematrix™ to stabilize crime scene biological samples for optimized analysis and room temperature storage from 2009-2011. She is the PI for a National Science Foundation grant that was awarded to CSULA in 2015 to establish the Center for Interdisciplinary Forensic Science Research as a research site within the NSF Industry-University Cooperative Research Center (I/UCRC) program. The Center will enhance research training and education in multiple forensic science disciplines, including Forensic Microscopy, Trace Evidence Analysis, Forensic Science Research Methods, Forensic Chemistry, and Applications of Forensic Science.

Dr. Roberts is currently collaborating with a consortium of European universities to develop a portable, inexpensive, and rapid method of dating latent fingerprints. Her publications are on topics related to trace evidence analysis, forensic examination of sexual assault evidence, and mitochondrial DNA analysis.

She was an elected member of the Technical Working Group for Education and Training in Forensic Science (TWGED) that was convened by the National Institute of Justice. The Forensic Science Education Programs Accreditation Commission (FEPAC) uses the report issued by TWGED in order to evaluate the academic standards of undergraduate and graduate forensic science programs.

Dr. Roberts is currently serving as the  Interim Executive Director of the California Forensic Science Institute.

Education

PhD     Forensic Science, Graduate School & University

Center, City University New York

M.Phil  Criminal Justice, Graduate School & University

Center, City University New York

MSc     Forensic Science, University of Strathclyde, Glasgow

BSc     Chemistry, King’s College, University of London

 

LISTEN: Link Goes Live Saturday 3-26-16 10 a.m. Pacific http://www.blogtalkradio.com/suspensemagazine/2016/02/23/crime-and-science-radio-with-special-guest-dr-katherine-roberts

 

LINKS: California Forensic Science Institute http://www.calstatela.edu/hhs/cfsi

CSULA School of Criminal Justice and Criminalistics http://www.calstatela.edu/hhs/crim

LA Times article, “Cal State L.A. graduate students hone crime scene expertise,” http://articles.latimes.com/2013/jul/27/local/la-me-cal-state-criminalists-20130728

Forensic Science Education Programs Accreditation Commission (FEPAC) http://www.fepac-edu.org

 

Diatoms: Microscopic Clues of Death By Drowning?

Light micrograph of radial and pennate diatoms under darkfield illumination

DIATOMS

What are diatoms? How do they help the Medical Examiner determine that a death was from drowning?

Determining that someone has drowned is not as easy as it might seem. The finding of water in the lungs isn’t enough. Sure drowning victims most often have water-filled lungs but if a corpse is tossed into a body of water, the lungs will often passively fill as the water replaces the trapped air in the airways and lung tissue. However, if the ME finds inhaled debris such as plant and water-born insects, etc. deep in the lungs, this suggests that the victim was breathing at the time they entered the water and inhaled the debris-filled water. But this isn’t always found.

So a method for determining drowning is needed. Diatoms might help. Though controversial and definitely not universally accepted as a sign of drowning, this search for diatoms is an interesting forensic science technique. And this search is not in the lungs, but rather in the bone marrow.

From HOWDUNNIT: FORENSICS:

The ME might also find clues to indicate that the victim was conscious before drowning by examination of the bone marrow. This might sound odd at first, but the key is in finding tiny creatures called diatoms within the marrow.

Diatoms are tiny single-celled organisms that scurry around in both salt and fresh water. They have silica in their cell walls and are very resistant to degradation. If the victim’s heart is still beating when he enters the water, any diatoms in the inhaled water will pass through the lungs, enter the bloodstream, and be pumped throughout the body, where they tend to collect in the bone marrow.

If a microscopic analysis of the marrow reveals diatoms, the victim must have been alive at the time of water entry. This technique may be useful in severely degraded or skeletal remains where no lungs or sinus tissues are available for examination. Unfortunately, diatom testing is not exactly that straightforward and is controversial. Some experts feel that diatoms are an inexact tool for determining if a drowning occurred. Some bodies of water contain no diatoms.

Also, they are found in air and soil and even on the clothing of the examiner. This makes contamination of the tested sample a possibility.

 

Howdunnit Forensics Cover

 

FORENSICS FOR DUMMIES Release Day

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Forensics For Dummies Updated 2nd Edition is now available.

Get it through your local Indie Bookstore or here:

Amazon: http://www.amazon.com/Forensics-Dummies-Douglas-P-Lyle/dp/1119181658

B&N: http://www.barnesandnoble.com/w/forensics-for-dummies-douglas-p-lyle/1013991421

 

The Mystery Readers Journal Forensic Mysteries Issue is Out

2016 MRI Forensic Issue

 

The Mystery Readers Journal Forensic Mysteries Issue is out and it’s excellent. Filled with wonderful and informative articles by some really fun folks. Janet always does such a wonderful job and this issue is a testament to that.

If you don’t belong to Mystery Readers International, you should.

Details and links to join are here: http://mysteryreaders.org

Here is my contribution:

THE QUESTION I GET

Every writer knows that creating an engaging and believable story is the primary goal of fiction writing. Taking readers into the story world and holding them there isn’t all that easy. And making basic errors in fact can all too often snap the reader right out of the story. A writer’s job is to make sure that doesn’t happen.

I have been consulting with authors and screenwriters on medical and forensic science story issues for the last 20 years and over that time have answered around 6000 questions. I am constantly amazed by the creative mind of an author. This is particularly true in the crime fiction and thriller genres. Equally impressive to me is that these are the authors who do the research, who try to get it right.

So, what are the most common things that I get asked? Poisons and rendering someone unconscious for varying periods of time are near the top of the list.

Many great murder mysteries, past and current, deal with poisons. Why not? They’re excellent tools for fictional murder. They require no physical confrontation and can even be set up so that the deed occurs days, weeks, or months later, when the perpetrator is far away. Clean and simple. No mess to clean up.

But poisons do possess limitations. Let me dispel one myth right up front—-there are no untraceable poisons. It might not be found but if it is looked for diligently enough and with the available sophisticated techniques, it will be found. Common poisons such as narcotics, amphetamines, barbiturates, and sedatives of various types are part of virtually every drug screen and therefore are easily found by the toxicologist. Others such as plant toxins, and many unusual chemicals, are more difficult. These require that the medical examiner and the forensic toxicologist have a high “index of suspicion” that a particular toxin is involved before taking the time and expense required to uncover it. These suspicions are often aroused by the symptoms that surround the victim’s death.

Often, for plot reasons, the author would like for the victim to receive the toxin but not have any symptoms until the next day and then suffer a quick and dramatic death. The problem? Poisons don’t have timers. Those that kill quickly and dramatically do so quickly and dramatically. Right here and right now. Not tomorrow, or next week. There are of course toxins that require several days to work their mischief but the victim almost invariably will become ill and spiral toward death over a period of time not suddenly collapse on cue.

In other scenarios, the author needs for a character to be struck in the head and to remain unconscious for an extended period of time. You’ve seen it before. The character is whacked on the head, placed in the trunk of a car, taken to some remote hideaway, remains unconscious for hours, and finally awakens when someone throws water in her face. Hollywood has been doing this for years. Unfortunately, medical science dictates that this is extremely unlikely. A blow to the head that causes unconsciousness but without significant brain damage is called a concussion. Boxers face this with every bout. The key here is that there is no significant brain damage in a simple, single concussion. The victim might go out but usually awakens very quickly and certainly by 10 or 15 minutes. Think about that boxer. He gets knocked unconscious and two minutes later he’s complaining that he was struck with a lucky punch. In order for the victim to remain unconscious for hours, there must be some degree of brain injury. A cerebral contusion (brain bruise) or an intracranial hemorrhage (bleeding into or around the brain) are two situations where unconsciousness can last for hours, days, or much longer. But here, the victim is truly injured and typically requires medical treatment in short order. A simple splash of water won’t do it.

So as you sit at your desk pounding out your next story, don’t assume that what you believe to be true is indeed true. This is particularly problematic if you don’t have a scientific background or if you get your understanding of science from television. Do your research. Seek out credible sources, Ask questions. Never underestimate the power of the word author. People like to talk about what they know so give them the opportunity.

Regardless of how you do it, get the facts right. That’s your job. And your readers will greatly appreciate it.

 
 
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