What Murder Mysteries Get Wrong About Forensic Sciences

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Elisa Shoenberger


Elisa Shoenberger has been building a library since she was 13. She loves writing about all aspects of books from author interviews, antiquarian books, archives, and everything in between. She also writes regularly for Murder & Mayhem and Library Journal. She's also written articles for Huffington Post, Boston Globe, WIRED, Slate, and many other publications. When she's not writing about reading, she's reading and adventuring to find cool new art. She also plays alto saxophone and occasionally stiltwalks. Find out more on her website or follow her on Twitter @vogontroubadour.

For many murder mystery enthusiasts, we are fascinated not only by the why of the Whodunit but the How. Who hasn’t fallen in love with Sherlock Holmes and his ability to tell your entire history for the red dirt stains on your pant leg and ink stains on your sleeve? We have had so many crime shows over the past few decades that feature forensic science, like NCIS, Rizzoli and Isles, Crime Scene Investigation and its infinite spin-offs. Or book series by Patricia Cornwell, Kathy Reichs, Beverly Connor, and more. But how much do these fictional shows and books get wrong about the actual practice of forensic science? 

Book Riot had a chance to talk to two professionals in the forensics field about how much murder mysteries get wrong in their depiction of forensic science: Justin Brower, Forensic Toxicologist at North Carolina, Office of the Chief Medical Examiner; and Victor Weedn, Chief Medical Examiner of Maryland.

Speed of Testing

In most shows and books, DNA tests, toxicology reports, and all the other forensic testing under the sun conveniently arrives to help the detective(s) solve the case. But as you may have guessed, that doesn’t happen in real life. “We don’t get answers within 30 seconds, or even an hour. Of course, that’s dramatization to fit the moving parts of the television show,” Dr. Victor Weedn explained.

Dr. Justin Brower added that “DNA can take months and months.” But he pointed out that the accuracy of waiting weeks and weeks or longer may not make for a good book. He says “if you’re in the first chapter and waiting for DNA, and they don’t get back until the last chapter of the book,  I understand why they have to make some accommodations and fit a little bit here just for the pacing of the book.”

The Sherlock Holmes Method

Timing isn’t the only thing that gets sped up for drama. The degree of specificity does too. “We don’t get answers that are so definitive and specific,” Dr. Weedn says, “Usually we’ll get: ‘It could be this or this.’ And it’s not: ‘This is it.’ It depends upon what you’re doing. Of course, DNA is pretty definitive. A fingerprint is pretty definitive. Toxicology test for this particular drug is pretty definitive. But there are just many other things that are not so good.”

For instance, he says, shows will say they found something under the fingernails and know that it is aluminum silicate from this beach. That’s not going to work in real life. Sherlock Holmes does a lot of speculation, Dr. Weedn notes, but “it’s not the kind of thing you go to court on.”

With respect to toxicology, things are much more certain. When they report on whether fentanyl, heroin, or cyanide is present, they are 100% certain, Dr. Brower said. They’ll screen on one specimen one day and then test on another specimen on another day by a different analyst and everything has to match up. “When you’re in a courtroom, being grilled by a defense attorney, you want to be 100%,” he pointed out.

But it’s important to know that there are three pieces to determining the cause of death. Just because cyanide was found in a corpse, it may not be the cause of death. Brower likened it to the fire triangle: you need toxicology, pathology that includes the autopsy, and then the investigation. “You have to really have all three of those pieces to figure out exactly what happened and establish the cause and manner,” he said, “So just because they have heart disease or something like that doesn’t necessarily mean that that’s what killed them.”

Coroner vs. Medical Examiner vs. Pathologist

Many shows and series mix up or combine the roles of coroners, medical examiners, and other forensic roles. “Coroners are elected officials, and they may or may not be a doctor,” Dr. Brower pointed out. He noted that for election cycles, he’ll see billboards to elect a Republican coroner or a Democratic one, and wonder: “How can you have a political affiliation for a coroner that helps establish cause and manner of death in the dead person?”

Medical examiners who conduct the investigations may not be a doctor but often have a medical background. Dr. Brower noted: “In North Carolina, EMTs, nurses, physician assistants, as well as doctors could be medical examiners.”

Then there are forensic pathologists who “are medical doctors with a pathology residency behind them and may even be board certified in forensics, and they’re the ones that do the autopsy,” Dr. Brower said. Some books have coroners doing autopsies.  

Dr. Weedn pointed out that often fictionalized accounts also mix up the work of the forensic scientists and the detectives. “We don’t go out and interview suspects,” he said.

Wrong Poison

Given the complexity and sheer variety of poisons out there, it’s probably not surprising that many shows and series may get the poisons wrong. “It’s really difficult to slip something to someone. If you think about putting like an aspirin or Tylenol in someone’s drink, and you look at what happened, you have like a clump of a pill down there,” Dr. Brower pointed out.

Death isn’t typically quick with poisons, and often very messy. It can often be slow and kind of ugly as well with bodily fluids coming out of orifices especially like in overdoses. “It’s not like on TV when somebody takes something and has a sudden collapse,” he added.

The Body

As an added corollary, Dr. Brower noted that many fictionalized accounts don’t get the after death part. “The decomposition starts pretty quick,” he said. “After a few days, the bodies are pretty much unrecognizable.” And if a person dies outside, scavengers and insects will make a real mess. 

And time of death estimates? Time of death might be narrowed to a range like eight to twelve hours. But Dr. Brower recalled, “A forensic pathologist told me once, if someone says they died at 11:30 a.m., that’s your suspect. Because you can’t narrow down a time of death like that. It just doesn’t work.”

What a Forensic Professional Reads

So what does someone in the field watch or read in the mystery genre? Dr. Brower said he avoids CSI and other shows in part because they get so much wrong, but also he has a tough job and sees everything. So he tends towards cozies: “they’re more lighthearted. They’re not graphic at all.” 

Truly Devious book cover

He named YA series like Maureen Johnson’s Truly Devious and Karen McManus’s One Of Us Is Lying or Joan Hess’s Magoddy series and Charlaine Harris’s Sookie Stackhouse series. “They’re easy bedtime reading,” he said.

But at the end of the day, he brought up the point that too much reality in forensic science in mysteries might do a disservice to them. “If you’re writing about a bank or something like that, and they don’t get some banking transaction 100% right. It’s not important to get things 100% right all the time, you’ll just drive yourself nuts. It’ll probably hurt your writing.” I think there is something very on point about that!

Thanks to both Dr. Brower and Dr. Weedn for sharing their insights! Also Dr. Brower has a great blog, Nature’s Poisons.

Want to learn about the science of dead bodies? Check out this Rioter list of non-fiction science books on the dead body. Or want more crime? Here’s a list of Best 2020 Crime Thriller Books