# Shell casings in CSI **URL:** \ **Category:** Factual Questions\ **Created:** [October 3, 2013, 3:30am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250 "2013-10-03T03:30:20Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dax-ion](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@Dax-ion](https://boards.straightdope.com/u/Dax-ion)\ **Post date:** [October 3, 2013, 3:30am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/1 "2013-10-03T03:30:20Z")
On TV crime shows investigators are always carrying on about shell casings. Are shell casing actually helpful in real life criminal investigations? If so, why don’t criminals use revolvers more often for close up crimes like murders and robberies where rounds per second don’t really come into play? ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [October 3, 2013, 3:51am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/2 "2013-10-03T03:51:45Z")
Revolver rounds have cases too. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [October 3, 2013, 3:58am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/3 "2013-10-03T03:58:11Z")
Shell casings can tell an investigator what brand/model weapon fired the round. If you know the round was fired from a Beretta, that eliminates a lot of S&Ws, Rugers, Colts, etc., and that’s useful information. ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [October 3, 2013, 3:58am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/4 "2013-10-03T03:58:15Z")
Some criminals have been known to use revolvers, although even with that you may be able to match the slugs from the crime scene to slugs owned by a perp. IN general, bullet casing evidence would likely only come into play if the cops have basically caught you already… in which case you don’t gain a whole lot. > [@Really\_Not\_All\_That\_Bright](#): > > Revolver rounds have cases too. Revolvers don’t drop their casings. They stay in the gun and must be emptied. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [October 3, 2013, 4:05am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/5 "2013-10-03T04:05:51Z")
:smack: I’m sure I knew that, but it didn’t seem significant. Until I re-read the OP. ---
**Author:** ![Airman\_Doors\_USAF](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@Airman\_Doors\_USAF](https://boards.straightdope.com/u/Airman_Doors_USAF)\ **Post date:** [October 3, 2013, 4:08am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/6 "2013-10-03T04:08:07Z")
> [@Dax-ion](#): > > On TV crime shows investigators are always carrying on about shell casings. Are shell casing actually helpful in real life criminal investigations? If so, why don’t criminals use revolvers more often for close up crimes like murders and robberies where rounds per second don’t really come into play? Shell casings, when fired, have certain markings unique to the firearm. The indent of the firing pin on the primer, the extractor notch on the rim, certain striations from imperfections in the barrel, all are unique at a certain level. Of course, they are all useless tidbits unless you have the actual firearm to create a new shell casing to compare it to. Some states require the submission of a shell casing in order to register the firearm. The belief is that it creates a way to pin down a firearm to a crime scene, because if the marks match it must be the same gun, and since the gun is registered it must be the same owner. Two problems with that- first, I can change the firing pin and extractor on any of my guns in no more than 5 minutes. Second, it is simple indeed to get a new barrel, which won’t have the same markings. Doing any of those is, as of now, legal, [except maybe in California](http://boards.straightdope.com/sdmb/showthread.php?t=440193). So, as usual, the answer isn’t simple. As for revolvers, if you find a shell casing from a revolver at a crime scene the criminal is an idiot, he’s using a Desert Eagle or some automatic that fires rimmed ammunition, or he’s wounded/dead and his gun is lying next to him. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [October 3, 2013, 4:13am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/7 "2013-10-03T04:13:17Z")
Casings show hammer marks. A picture from a real CSI ! > **[ArrestingImages.com is available at DomainMarket.com](https://www.domainmarket.com/buynow/arrestingimages.com)** > > Domain for Sale. ArrestingImages.com. Request Price. What Are the > Advantages of a Super Premium .Com Domain? Increased Traffic. Search Engine Ranking. Brand Recognition. > Immediate Presence. Higher Profits. Great Investment. #1 in Premium Domains.... Also the contact marks, and stuff , eg GSR or cleaning products, even metal alloys, from the chamber may be matched or more often shown to be inconsisten.t Can at least rule OUT a gun pretty well, “nope, that gun there did not put those That there !” , real quick, no CSI needed, and that way they are not giving up the search for the actual weapon too early. ---
**Author:** ![Dax-ion](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@Dax-ion](https://boards.straightdope.com/u/Dax-ion)\ **Post date:** [October 3, 2013, 4:46am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/8 "2013-10-03T04:46:20Z")
I saw the movie Mr. Brooks with Kevin Costner and there is a scene where his character enters a home intending to kill two people with two gunshots from a hand gun and he tapes a plastic bag around his gun and gun hand to capture the ejected casings and I was all WTF why wouldn’t people IRW prefer a revolver for hold-ups, burgleries, and close killings anyway? Is it that common criminals are to wimpy to supply the PPI to pull a revolver trigger or is it a fashion statement? I figure at close range people would be a whole lost more taken with your seriousness if you pulled a revolver on them. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [October 3, 2013, 5:06am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/9 "2013-10-03T05:06:21Z")
You might need the extra rounds if your marks fight back. ---
**Author:** ![doorhinge](https://avatars.discourse-cdn.com/v4/letter/d/a5b964/32.png) [@doorhinge](https://boards.straightdope.com/u/doorhinge)\ **Post date:** [October 3, 2013, 5:35am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/10 "2013-10-03T05:35:02Z")
> [@Dax-ion](#): > > On TV crime shows investigators are always carrying on about shell casings. Are shell casing actually helpful in real life criminal investigations? If so, why don’t criminals use revolvers more often for close up crimes like murders and robberies where rounds per second don’t really come into play? (underlined for my convience) Technically-speaking, revolvers can be fired faster than semi-automatics and even fully automatic pistols. A revolver’s action is a direct mechanical link and is only limited by how fast you can pull the trigger. Semi-auto and full-auto actions have to wait for the action to cycle before it can be fired again. Usually, revolvers hold 5, 6, 7, 9 rounds of ammo. 5 and 6 round models are the most popular. Pistol can hold from 4 to 30 or more, depending on the model and magazine capacity. That might be a deciding factor??? Shell casing might be useful to secure a conviction in court, if, they are in reasonably good shape and police have found the firearm that matches the case markings. It’s extremely simple to modify/alter a firearm to prevent real-life CSI’s from making a shell case to pistol/revolver match. ---
**Author:** ![Dax-ion](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@Dax-ion](https://boards.straightdope.com/u/Dax-ion)\ **Post date:** [October 3, 2013, 5:52am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/11 "2013-10-03T05:52:30Z")
I am imagine a crime where the perpetrator is not expecting the victim to respond with gun fire. Criminals attacking other criminals or cops or guards might expect a shoot out but probably with a hold up, burglary, or contract killing you are expecting to get the job done with fewer then five shots. You could carry a large magazine automatic for tactical retreat in the case of armed response but wouldn’t you want an revolver if you are going to straight up kill someone? A case that comes to mind is a guy who was lured to Manhattan a couple months ago in connection with a drug deal gone bad. Some guys drove up in an SUV outside his hotel in mid-town and in the middle of the day one of them casual walked up behind him as he left the hotel, casually fired a gun point blank into the back of his head and casual strolled back to his car which causally drove off. It was caught on security camera and the shooter was calm and composed and moving at a leisurely pace through out. I would think a small revolver would be preferable to an automatic for such a job. The guys in the car might want Uzis to spray around with if trouble popped up but I would think the shooter would be fine with a revolver. Same story with burglarizing a house or robbing a convenience store… you might encounter an armed response but a prolonged shoot out is unlikely, a more reliable and less traceable hand gun seems in order to me. This brings to mind an other question… for the kind of close work I am imagining, is there any advantage in lethality to a large caliber over a small caliber gun? Don’t .22 slugs just kind of bounce around inside of people tearing them up rather than blowing right through them? ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [October 3, 2013, 8:09am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/12 "2013-10-03T08:09:11Z")
Modern techniques can pull fingerprint evidence off [fired bullet cases](http://www.newscientist.com/article/dn14625-hot-bullet-casings-can-still-finger-the-criminal.html#.Uk0lsW0_-tc). ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [October 3, 2013, 8:28am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/13 "2013-10-03T08:28:37Z")
In addition to everything that has already been mentioned, shell casings also show you roughly where the shooter was standing when the shots were fired. This can be very useful in reconstructing the crime scene. ---
**Author:** ![Airman\_Doors\_USAF](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@Airman\_Doors\_USAF](https://boards.straightdope.com/u/Airman_Doors_USAF)\ **Post date:** [October 3, 2013, 10:20am UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/14 "2013-10-03T10:20:57Z")
> [@Dax-ion](#): > > This brings to mind an other question… for the kind of close work I am imagining, is there any advantage in lethality to a large caliber over a small caliber gun? Don’t .22 slugs just kind of bounce around inside of people tearing them up rather than blowing right through them? This question will take us off on a tangent you would not believe (caliber wars and stopping power being the two favorites), so rather than go down that road let’s just say that the caliber is irrelevant if you properly place your shots. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [October 3, 2013, 1:17pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/15 "2013-10-03T13:17:59Z")
> [@doorhinge](#): > > Technically-speaking, revolvers can be fired faster than semi-automatics and even fully automatic pistols. Doubtful, in any real-world sense. Various Googling suggests that an extreme rate of fire with a revolver may approach 8 rounds per second, whereas some automatic pistols are capable of 12+ / sec. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [October 3, 2013, 1:19pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/16 "2013-10-03T13:19:28Z")
> [@Airman\_Doors\_USAF](#): > > This question will take us off on a tangent you would not believe (caliber wars and stopping power being the two favorites), so rather than go down that road let’s just say that the caliber is irrelevant if you properly place your shots. Wise thinking. ---
**Author:** ![wguy123](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wguy123/32/3161_2.png) [@wguy123](https://boards.straightdope.com/u/wguy123)\ **Post date:** [October 3, 2013, 2:42pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/17 "2013-10-03T14:42:49Z")
> [@Xema](#): > > Doubtful, in any real-world sense. > > Various Googling suggests that an extreme rate of fire with a revolver may approach 8 rounds per second, whereas some automatic pistols are capable of 12+ / sec. Yep - takes nearly 3 seconds to get off 12 rounds from a revolver: https://www.youtube.com/embed/lLk1v5bSFPw?feature=oembed&wmode=opaque With Jerry, those were all probably A’s. ---
**Author:** ![Dax-ion](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@Dax-ion](https://boards.straightdope.com/u/Dax-ion)\ **Post date:** [October 3, 2013, 3:08pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/18 "2013-10-03T15:08:31Z")
Still I guess my question then is do common criminal use automatics simple because of fashion or is it availability or what? I guess I imagine it is because the trigger pull requires less pressure then it does on a revolver? Or are they afraid the hammer will catch on clothes? I guess some criminals use revolvers though since I read of a case where a cop saved himsellf by jamming part of his hand between the hammer and shell when a guy tried to shoot him at close range. Tore up his hand but he subdued the guy. Can’t remember when I read that. Anyway, I just would think I would want a small revolver for up close range work since I would think being easily concealed and easily pulled out and not kicking out additional evidence would be attractive. Finger prints and shooting location are good points. Are automatics heavier or lighter than revolvers? I have only shot a .22 rifle. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [October 3, 2013, 3:19pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/19 "2013-10-03T15:19:28Z")
> [@Dax-ion](#): > > Are automatics heavier or lighter than revolvers? Yes. 😃 Could be heavier, could be lighter, depends on the model, caliber, load, grips and a bunch of other factors. My .44 Special revolver is heavier than my .32 ACP semi-auto, but my .40 S&W semi is heavier than my .38 Special revolver. ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [October 3, 2013, 3:39pm UTC](https://boards.straightdope.com/t/shell-casings-in-csi/670250/20 "2013-10-03T15:39:55Z")
They are sources of information about the crime. Good police work means you don’t overlook any source of information. You’ll never know what might be useful and in any investigation there are tons of information that is collected on this basis. Most may not pan out. [Next page](https://boards.straightdope.com/t/shell-casings-in-csi/670250.md?page=2)