Fiction readers love drama, and drama nearly always involves some type of crime. When something unspeakable happens, like murder, who doesn’t feel satisfaction when the evidence turns up and the bad guy is brought to justice—as long as we’re taken on a wild ride along the way?
To gather information (and inspiration) for the spin-off mystery series I’m working on, I recently attended the Writers’ Police Academy’s 2019 “MurderCon” in Raleigh, North Carolina. Spearheaded by crime writer Lee Lofland, WPA’s mission is to give writers the information and hands-on training they need to write convincingly about law enforcement, first responder activities and crime detection. 
This year’s series of workshops focused on the various ways science (called “forensics”) is applied to the gathering of evidence. For two and a half very busy days, I learned the basics about everything from shoe and fingerprints, blood splatters and firearms, to how a crime scene is investigated, the different manners in which death occurs, and what happens to the body after death. The experts could only scratch the surface with us lay people, but I can safely say we all came away with a renewed respect for the challenges law enforcement faces, and a much better idea of all that we don’t know, which helps tremendously when it comes to researching for a particular story.
Several aspects of evidence-gathering stuck with me and I expand on them a bit here:
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courtesy locardslab.com
Some instructors referred to “Locard’s Principle.” Edmond Locard was a French criminologist who became known as the “Sherlock Holmes of France” and established the first police laboratory in 1910. He coined the axiom that “every contact leaves a trace.” In other words, in any given crime scene, the criminal will leave some sort of indicator that he or she was there and something of the crime scene will leave with them. Finding what connects the suspect to the crime scene is what forensics is all about.
- Believe it or not, violent crime, as measured per 100,000 people, has gone down since colonial times. There was a spike in the rate between 1960 and 1991 (the reasons for that vary), but since then the rate has, with a few exceptions, stabilized and retreated. Experts continue to debate the reasons behind the drop (e.g., more prisons, rising incomes, government programs, less crack cocaine). Invariably, however, Americans, when surveyed, always say the rate is rising!
- Even when the naked eye can’t see shoe prints, investigators—with the right equipment—can. Most perps don’t wear dress shoes when they commit crimes but certain high-end athletic shoes turn up frequently among the criminal class. Fortunately, not all shoes (even the same brand, style and color) are created equal; their prints can be pinned down to individuals through distinct wear patterns on the sides and soles. Each of us, it turns out, has a distinct way of wearing out our footwear, almost like a fingerprint. So why don’t more suspects ditch the shoes that might be linked back to them? Because the shoes are often a status item and cost a lot of money—bad guys are practical, it seems!
image via gtdist.com
- Guns are here to stay. Although I’m a chicken when it comes to guns, I support the Second Amendment. With all the requisite safety measures in place, I was able to handle a wide array of weapons up close and personal, including some that I’ve only researched on paper. Fortunately, the Sig Sauer P238, which I researched for my latest novel The Jade Hunters, fit the story perfectly! I learned that while 60-70% of murders are caused by dangerous thugs shooting guns, those guns are usually cheap, often stolen, or bought illegally. One of the questions asked of a gun seller on the street is, “Is there a body linked to this gun?” It’s bad enough when investigators connect a suspect to a gun—but for a crime that he or she didn’t commit? Even criminals know that’s a bridge too far. I also learned that the bullet from a .45 will go through several layers of drywall; shorter barrels aren’t accurate from a distance and should be used for defense only; and the very last thing you want to be facing is a shotgun at short range. It’s unrealistic to think that Americans are going to willingly give up their weaponry; solving our current mass shooting problem must be dealt with in other ways.
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image via floridaforensicscience.com
Now you don’t see it, now you do. No matter how hard a murderer tries to clean up blood—with bleach, peroxide, alcohol, or other household cleaner—investigators have the tools they need to determine if blood is present, using chemicals such as Luminol, which glows when reacting with blood that’s not visible. Stay away from veggies such as radishes or green beans, however; they can give off a false positive. CSI technicians can also detect if a stain is in fact blood, even though it’s dried and looks like a spilled milkshake. The chemical used for that test is called “phenolphthalein.” In one of the workshops, we conducted a test and the chemical was able to detect literally “a drop in a bucket.” Finally, where it’s obvious that blood is present, the location and character of the splatters can tell a lot about the murder, such as how long the body lay in one position while bleeding; what direction the blow came from and what objects if any were removed, leaving a blank spot where blood stains should be. Trained investigators can often deduce the entire crime scenario by blood evidence alone.
- Maggots like their creature comforts. I learned a lot about how the body decomposes (crucial in determining a death timeline). Mummification is fascinating, but one of the most interesting processes that often occurs beforehand involves the eating habits of those disgusting fly larvae that feast on dead bodies. All else being equal, if you leave a body wrapped up (for example, in a tarp) outside, and you leave a similar body exposed to the elements, after a certain amount of time (which varies according to climate, nearby bugs, foraging animals, etc.) the wrapped body will be completely gone down to the bones, while the exposed body will most likely retain an outer layer of skin. That’s because maggots prefer shade and keep the outer skin on to stay cool—there’s no need to do that with the tarp-wrapped body because the tarp provides the protection. Another discovery: there are several “body farms” around the country where scientists study body decomposition to help teach forensic investigation. The first one was started at the University of Tennessee in 1987 and the largest is located on more than two dozen acres as part of Texas State University. You can even donate your body to one of these research facilities once you’ve gone to the great library in the sky!
You may wonder how so many intelligent, highly trained and hard-working people can spend their lives dealing with such grotesque matters; I certainly did. But one of the forensic pathologists who spoke at the conference explained it perfectly. She said that she works in forensics to give a voice to the victims who can no longer speak for themselves. Even though they’re no longer with us, they still deserve justice.
What aspects of crime detection do you wonder about? Let me know what you think.
