Forensics for Writers: Part I

I don’t know that we have any mystery writers who read the blog, but Sarah Hoyt writes ’em, and I probably will one of these days… and in the meantime, I’m most of the way through a degree in it. Well, ok, not mystery. I’m studying to become a Forensic Scientist and Investigator. It occurred to me that many of the writers who come here use mystery as sub-plots, and sometimes the main plotline. So… why not? After all, as we were joking in class the other day about what kind of castoff a cast-iron skillet would make, I can search topics with impunity that my professor complained would get her in trouble. I’m a writer!

I don’t know how long this series will be, I will let the commentators determine that to an extent. If you have questions, ask in comments and I’ll add on. I could, literally, write a book about this. I’ve certainly read enough of them. I’m not planning on doing that here. I thought I’d hit the highlights of what forensic science is capable of now, and what it may be in the not-to-distant future.

So what is forensics? How about criminalistics? I am fairly sure that our readers are well aware that it’s not CSI, and as shown on television is a far cry from reality. Forensics is, broadly,  the use of science within the parameters of criminal and civil laws in the criminal justice system. Forensic science can be and is applied outside that system as investigative measures but strictly speaking forensics is science and the law. Within the field of forensics there are specialties: criminalistics, digital forensics, engineering, odontology, pathology, biology, physical anthropology, psychology, questioned documents, toxicology… a cross section of both physical and behavioural sciences. Criminalistics is what could also be referred to as the scope of a crime laboratory – much more the physical side of evidence than the esoteric workings of the human mind.

I think every textbook I have had on forensics points out, quite properly, that the science has its roots in fiction. A Conan Doyle’s Sherlock Holmes used many of the principles that would be refined by his readers into the nascent field of pursuing lawbreakers with science. Startling, to realize that storytelling would lead to, well, this 1887 excerpt from A Study in Scarlet speaks volumes:

“I’ve found it. I’ve found it,” he shouted to my companion, running towards us with a test tube in his hand. “I have found a reagent which is precipitated by hemoglobin and by nothing else… Why, man, it is the most practical medico-legal discovery for years. Don’t you see that it gives us an infallible test for blood stains?”

I could happily talk about the history of the field for some time – I have a paper written by a brilliant man who applied forensic principles to the killing fields in Serbia in the early 1900’s, one of the precipitating factors in the first World War – but the modern relevance is more fitting for this post, and if any of you are interested in historical methods we’ll separate that into a different part. It is pertinent to know, for instance, that you cannot have DNA used in a trial prior to 1987, as that was the first time it was accepted in court.

Which is another thing. What can be accepted in court, and who makes that decision? In 1923, a case regarding the polygraph came before the court, and the court rejected it with a particularly interesting turn of phrase: “Somewhere in this twilight zone the evidential force of the principle must be recognized.” Frye v. The United States established that science in the courtroom must be an established, valid method that was accepted by the scientific community. In other words, the scientific method, of experimental results that can be replicated, must have been applied to the results brought into the courtroom. The second major case, which to me seems somehow at right angles to the Frye decision, was Daubert v. Merrill Dow Pharmaceuticals, Inc. which ruled in 1993 that the ‘general acceptance’ standard of Frye was not absolute. Scientific evidence was now permitted on the sufferance of the trial judge. Judges, initially by law at the Federal level but in practice at the State level as well, were now to assume the ultimate responsibility in being a gatekeeper for the evidence presented before them whether scientific or simply that of an ‘expert’. Finally, the last significant case we will want to pay attention to is the 2009 Melendez-Diaz case, which requires that the forensic analyst appear in court, as the accused has the right to face their accuser. The repercussions of that decision are far-reaching and still being explored.

I’ve come this far, and you haven’t even seen a bit of blood spatter, I know. For most of us writing mysteries, none of this makes much difference. Which leads me down another rabbit trail (last one, I promise!) of “what sort of mystery is it?” There are all kinds of mysteries, from Police procedurals – where all the nitty-gritty of the law matters, very much – to cozies, where the protagonist might not know any of this, even though the author does. The first rule of a crime scene – touch nothing, record everything – means nothing to the cozy protagonist, and in fact their interference and ignorance may be an important part of the plot and conflict. In a detective story, removing (or inserting) something from the scene may be a more willful action. But in a police procedural where the protagonist has a clue, they will proceed with great caution when they first come on the scene. Which, by the way, is almost never as the first responder. Their first action most likely will be to take the statement of the first officer on scene. From there, they will continue, slowly, taking notes and photographing before touching anything. It’s not a fast process, something an author needs to keep in mind. Even processing a simple robbery can take hours.

Something else the TV shows get all wrong. A lab boffin (which is what I’m training to be) is not the field investigator, and they have very different skills and perspectives. It has been amusing to sit in classes with police officers who are training for the field end, and flinching when they talk about the science and miss the mark. On the other hand, I’m just as happy to not be the person who will be standing ankle deep in soot and debris and water at temperatures just above freezing carefully shoveling it out during an arson investigation. When you’re writing, keep this in mind. The investigators send the evidence to the lab, the lab analyzes it and returns results. The lab people don’t go out in the field. The lab boffins might not even be law enforcement, there are a lot of private labs these days.

And with that, our toes at the fringes of the place where all the action is, the crime scene, I will leave you until next week. Feel free to ask questions in comments, and I’ll start shaping what I want to say with what you want to know about physical evidence.



37 responses to “Forensics for Writers: Part I

  1. It would be great to have a young adult mystery that used forensics correctly, with an appendix that actually EXPLAINED the science, with equations and everything.

    • Depends on what you’re looking for in equations… Superficially, other than calculating the angle a blood drop was traveling when it hit, there’s not a lot of math in the investigation part of this.

      • Basically, an “how it works”. For example, why does the technique to detect blood stains work? How does DNA analysis separate strands to create a unique profile. That kind of thing.

        • I know when my daughter was 10, and fascinated with it, I had trouble finding an age-appropriate book for her to read more on it. So yes, that’s a good idea.

          • Hum… reminded me of the short story teacher who gave us an assignment to use one (1) very unusual word in a story and work in the explanation of the word so that by the time the reader finished the story, they knew the word and its meaning. My word was incunabulum, incidentally. I would think a series, with each one bringing out one technique, would work better than the appendix.

  2. emily61

    The Flash is supposed to be a forensic scientist. Since it’s a comic book based show I’m sure it’s not accurate. Was the fact that her husband was an archaeologist helpful to Agatha Christie as a writer? Lord Darcy is an interesting series of mystery stories set in an alternate Europe. The forensic specialist was a wizard. I think Randall Garret is under appreciated.

  3. There was a lawman in the American West who used forensic techniques prior to Doyle’s stories. He would do things like recover bullets. Sorry, can’t remember his name.

    Putting a limit on forensics is my problem. The closest story with forensics is a lawman in 1870s Georgia who notices a powder burn that shouldn’t exist – unless someone was covering up a murder. His forensics is limited to noting the size of the bullet holes and that the would-be robbers carried Colt Army while those who returned fire had smaller – and easier to conceal – caliber revolvers. Except for the guy with a double-barreled shotgun. And yes, he checks out the shot pattern at the scene to see if that squared with the story.

    But there is no autopsy of the victim. No one even thinks of it. He just goes to inspect the corpse as it’s being made presentable for viewing and notices the head wound has a powder burn that shouldn’t have happened if he was shot by one of the bandits. But the bullet hole was made by a large caliber weapon, such as a Colt Army revolver. And that’s the limit of the forensics.

    • Stories – and forensics in stories – date much further back than Holmes. But it’s accepted that the Holmes stories were responsible for sparking interest in applying science to criminology and inspriring many who then went on to create the field as we know it.

      • Paul (Drak Bibliophile) Howard

        Years ago, I read The Century of the Detective by Jürgen Thorwald.

        It was interesting to read about how science impacted detective work.

        Unfortunately, it was published in 1965 and doesn’t appear to be in print now.

      • TRX

        A lot of obvious and worthwhile things were re-invented or re-introduced for years or decades before they caught on.

  4. BTW, Lodge makes cast iron frying pans with customized logos on the bottom. Just the thing to make a distinctive impression.

  5. Oh, nice. I keep sliding into mysteries at least as a subplot and sometimes the main plot. Of course I’m looking for evidence that a murder, or arson was committed by magic or other means. But it would be nice to be right about the other means.

    • You too? Rada’s pestering me about a mystery on a starliner (no, she won’t tell me why she’s even on board). I don’t DO mysteries! OK, besides the one about the professors who get murdered, but that’s different.

    • And you can always go through the steps, eliminating the possible… until what is left is impossible. Voila! Magic.

      • I’ve got a “No obvious signs of accelerants, indications of multiple points of origin.” And something about more needed for a definite indication of magical arson. But I hate being vague because I can’t find or it didn’t occur to me to research things like specific signs of death-by-bee sting. (Thank you, Beta Readers!)

  6. I don’t remember where I read this, but it goes back before guns–it was more knights in shining armor and swords. The *leader* of a band of merry men suspected that one of his men had committed a murder. All the swords were shiny; no blood visible. So he had his men stand in a circle around an anthill and place their swords on the ground in front of them. Gradually the ants went to one of the swords, and there was the culprit!

  7. Draven

    NCIS producers have generally acknowledged that yes, Abby would be like six people…. (and that, yes, more than just Gibbs would be ex-military)

    • aacid14

      That is usually the thread I accept with any procedural. Multiply the number of Tech’s by some scalar and see each character as two or three people

  8. The closest to mystery I come (though I’m thinking I need to give Dolly an investigation, as the Troll Guard is supposed to be the police force for the East College campus (in Ohio, a large enough college campus COULD be incorporated as a city, thus needing an official force of sworn officers)) is Armed Citizen in which Dolly is tried for murder, by a combination of a corrupt prosecutor and a conspiracy of her enemies and resulting from her use of her service weapon to foil a bank robbery. The central point of jeopardy rests on her taking out three of the bank robbers in a little over a half-second, including two head-chest double-taps, and the claim of the prosecutor that it was impossible, and therefore she must have had an accomplice she’s refusing to name. What they don’t tumble to, and becomes the major jeopardy of the story is that she was able to make the kills because of her enhanced abilities as an artificial person, the exposure of which would reveal her Big Secret, and strip away any protection she has from Upothesa (the alliance of Gods and humans which protects her — to over-simplify it).

    I tell you that to tell you this: along the way, I did considerable research on Ohio law regarding murder and the use of firearms (It’s not illegal to shoot a firearm IN a structure, but it is illegal to shoot one inTO a structure — that kind of thing.), the privileges, duties, and limits on the use of firearms by sworn officers of the law, and so-forth. But I found VERY murky the rules of procedures in actual trials. I know there are books, but; poor, starving author. What I would find most helpful would be — not so much explaining things as laying out WHERE you can find these things.

    (I would love to brainstorm this with you over lunch — I’ll buy this time; tell Sanford to leave the plastic in his wallet.)


    • We’ll have to come up with some time 🙂 I have midterms spread out over the next couple of weeks.

      And Yes, I can probably help with some of that, although I will caution anyone that I’ve taken classes, studied, and read, but I am not a lawyer nor an expert. This is for writing purposes only.

      • Mark Alger

        Well, real soon now is probably not in the cards, at least not for this project. I am, as we all know, out of work and needing to get that sorted. So that’s occupying my time for some time. And this project has been back-burnered for 16 years (mostly because of these issues and how to work them out) and its place in the current rotation of planned stories puts it about two years out at present. So…there’s time. 🙂


        • Have you considered looking for a local police force offering a citizen’s academy? It’d not only give you a look inside, but let you ask lots of questions with the friendly officers.

  9. aacid14

    My in progress is a thrill/mystery style but I don’t focus much on the raw forensics since its from pov of agent investigating.

    • There are two sides – you wouldn’t, for instance, get into the details of how to run a gas chromatograph analysis, but you might be interested in the results (and what they mean to your investigator).

      • aacid14

        Yep. My family are med Tech’s so understand a good chunk. But there are a few blood tests that come up

  10. Reality Observer

    Unlike many here (apparently), I have nothing right now in the queue that would require forensics.

    OTOH – who ever knows? Keep these coming, please.

    OT – just finished The God’s Wolfling; first book on the new Fire. Fantastic!

    • I shall continue if for no other reason that it’s an excellent way to actually use (and reinforce) what I’m using.

      And I’m so happy to hear that! Thank you 😀

  11. kenwd0elq

    Forensic science? Robert Bruce Thompson, formerly best known as an author of computer books, has written a series of advanced high school level science laboratory books, including chemistry, biology, and forensics. I understand that they are pretty good; reading his blog ( as he explained some of the experiments was fascinating.

    Thompson is currently writing a prepping guide, which I expect to be definitive on the subject.

  12. :waves: I’m here. I do mystery/suspense, etc. I think every genre has a little mystery/suspense in it. Otherwise, it’d be boring. I don’t necessarily get into the nitty-gritty procedural stuff, but I’ll be reading your posts with great interest. Every bit of knowledge adds to the whole. =o)

  13. BobtheRegisterredFool

    I read a lot of children’s mystery when I was young.

  14. Bjorn Hasseler


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