The Ol’ Gun was Recently Fired “Test”…Not!
Gun recovered at crime scene
I’m sure you’re all familiar with this scene. The detective finds a gun in the suspect’s house, or car, or wherever and after glancing at it or possibly sniffing it they proclaim “Ah ha! This gun was recently fired”. I’m not sure how this idea ever took hold but it has become so prevalent that a lot of authors and readers might actually believe it. Now, it would be awesome if we could actually determine such a thing but, alas, we can’t. Nor can we tell if a gun was “recently” cleaned. It sure does make for a memorable statement though.
We can tell if a gun has been cleaned since last being fired. We can determine that a gun is clean and that it may have excessive gun oil or something like that but we can’t quantify the duration of that condition. Now this could be informative if police stop a guy in the vicinity of a shooting and he’s carrying a gun. If the gun is “clean” they might eliminate him as the shooter. However, this would assume that he didn’t use another (second) firearm or that he didn’t use something like a Boresnake to quickly wipe the barrel.
Most firearms examiners will run a new cleaning patch down the barrel before test firing the weapon. This maycapture things like unburned gunpowder (useful in comparing to GSR or fired cartridges found at the crime scene), blood spatter, or other trace evidence which may help link that gun to the crime. But CSIs or detectives can not tell that a gun was recently fired (or not fired) simply by looking at it.
Posted on July 20, 2011, in General, The Crime Scene and tagged crime, Crime Scene, csi, detective, fiction, forensic photography, forensics, GSR, gun, gunshot residue, thriller. Bookmark the permalink. 7 Comments.
That is tremendously helpful information, f4f. Like everyone else, I never even doubted that an trained investigator could sniff the barrel of a gun and proclaim its state of having been fired or not fired recently. I would have been absolutely chagrined to have this sort of inaccuracy in my book after it has been published. You’ve saved me from a very red face. I’ll pass it on to other writers…or better still, just direct them to your site. I’ve seen some very good stuff go by here lately (yes, I can sniff the page and tell if the recent writing is any good or not
Any bites on your book yet? Do you write short stories as well? I have a reason for asking and will email you after you answer.
Hi Sandra, nothing solid on the book but it’s being reviewed by a couple of agents (really slow process). I have had several ideas for some short stories (one that I really like somewhat outside my genre)but in addition to the second book, the blog, and scientific research papers I get very little sleep or free time right now. As to the article, ther is a difference between a hunch or lead and a provable fact you can swear to in court. It’s very common for CSIs and investigators to form an opinion upon which they choose a certain course of action. In the old days we called it following your gut. So for a character to sniff the barrel and be convinced that the gun was fired recently is fine but just recognize as the author that they couldn’t go into court and testify to it. Additionally, if that hunch was used to justify some action that would otherwise require a warrant they will likely be in violation of some policy or maybe even a law depending on the circumstances. I hope that doesn’t muddy the watter further. Maybe a blog on gut instinct vs. scientific fact is worthwhile. Another one could be on the dangers of sniffing certain types of evidence. Thanks for engaging my brain.
Hi Tom,
This is a great blog and resource.
Thanks!
Will you be following this up with a post on the test of gun residue on hands after firing? In some fiction books I read that seemed to be the catch all to prove someone had fired a gun. Then in other novels doubt was cast on this type of evidence, though off hand I can’t recall what the problem with this kind of evidence was. I think this is the GSR test. In any case, I’d love to learn more if you have time to touch on this subject. Or, if you have already blogged about this, please point me in the direction of your post. Thanks!
I actually did write about this a little over a week ago and I thought I had lniked to it in the article. If not here is the link. http://forensics4fiction.wordpress.com/2011/07/11/gunshot-residue-gsr-tests-what-do-they-really-prove/
Take a look at it and let me know if I can help explain anything further. Tom
Ah, but being factual never has been much of a concern to Hollywood.
I know what you mean. In truth, as a fiction writer, we all have to stretch the “truth” to create an interesting story and readers expect and accept that. But…we can also make an effort to limit the degree to which we take our writing liberties.