Can a gun be traced to a crime using balistic test and comparisons? Like can a gun leave a specific mark on casings and bullets similar to say how humans leave fingerprints?
>>28332011
you're looking for something called microstamping. california is the only state that requires it on handguns to be approved for their safe handgun roster which is a list of handguns californians are allowed to buy new. to date, not a single handgun has been added to the roster because of microstamping. not a single company has implemented it.
>>28332035
So all that New Detective stuff about matching fired bullet casings and bullets to specific guns is bullshit?
>>28332011
The Maryland State Police formerly did a 'ballistic fingerprinting' from every legally purchased Handgun in MD, by firing 2 shots into something and recording it.
It helped to solve zero crimes.
>>28332011
The short answer is yes. They can compare the marks on the casings found at the crime scene to casings ejected from from firing the suspected weapon. Same goes for the bullets. But here's the real question:
>Let's say someone kills someone else with a rifled slug round out of a shotgun, and either doesn't eject the spent shell or does eject it and picks it up. Since most shotgun barrels are smoothbores, how could they trace it back, if at all?
>>28332011
it sounds like someone just saw the Great Mouse Detective for the first time
>>28332011
>Can a gun be traced to a crime using ballistic test and comparisons?
Depends if they have a comparison sample. They basically have the following data points assuming you left the case.
>Caliber
>Type of ammo used (headstamp)
>Type of ammo used (bullet style)
>Type of ammo used (weight)
>Firing pin information (Impact style and depth)
>Basic rifling information (polygonal or traditional)
>Ejector markings
Now given this information you could narrow it down to something like "Winchester ranger 9mm 124gr bonded jhp fired out of a short autoloader using polygonal rifling with a distinct rectangular primer indentation" based off that information you could come up with a gun that would fit that, basic statistics would narrow it down further since they are most likely using something common. Some guns do leave identifying marks (look at some glock brass compared to any other 9mm brass) that can be sued to narrow down the model further
There is microstamping but its nearly impossible due to the scale you need to engrave on
>>28332053
Basically you can only come up with a small list of gun models possibly used but nothing that can give you the actual gun used in the crime?
>>28332044
no, it's absolutely correct that chambers, bolt faces, extractors and firing pins leave unique marks on fired casings. you can tell that two casings have been fired from the same gun. it's just not that useful because you need to be in posession of the gun to compared fired casings. vii
>>28332050
That's the scene I think of every time someone asks this, and I didn't even remember it was from that movie.
>>28332102
Small list of models and ammo types
Then you use your other clues to find suspects and nail them with them using the info about gun
>Jim is dead
>9mm glock 26 according to ballistics
>Dave hates jim and cant be accounted for during the murder window
Not enough for a warrant
>Dave also recently purchased a glock 26
Now this is podracing
>get search warrant based on above
>take Daves gun
>fingerprint it with finer points of comparison
>it matches
>Dave goes to jail
>>28332105
Rite so no two guns leave the same markings however a gun usually leaves the same markings every time its fired
>>28332120
Unless you swap barrels or firing pins. Which is easy enough on most semiauto handguns.
>>28332120
>so no two guns leave the same markings
This isnt entirely true its possible its just very slim. Like two people having the same prints or twins hitting on a DNA match. Mass production guns will obviously leave less ballistic data than a custom 1911
>usually leaves the same markings every time its fired
In most cases yes. All points may not match but if >60% do than it is pretty concrete. DNA never matches 100% either but it works.
>>28332131
You would want to do the following to make a ballistic nightmare
>buy gunshow revolver in cash
>buy gunshow reload ammo for said revolver
>commit crime
>thermite gun
>throw slag in river
If you have to use an autoloader you basically want to bin the entire slide but that would be pretty fucking obvious with matching serials and what not. So you would need untraceable ammo source, barrel source, ejector source and firing pin source that couldnt be tied to you at all.
>>28332131
>swap barrels or firing pins.
And for fucks sake, don't just keep them or throw them in the trash.
>>28332145
This.
Thermite is Gods way of telling metal "Fuck you"
If the police want to take a pool of slag back with them, they can while you laugh behind a heat shield.
>>28332115
i fucking loved that movie when i was a kid.
>>28332145
Note the use of reloads, this would make things difficult considering the consistency is minimal and the bullet loadings will be unique. Furthermore since reloads are unique if you were found in possession of reloaded ammo you have the defense of "Lol its loaded uniquely you have no proofs that murder bullet was from this ammo source"
>>28332011
Ballistics can now only be used as circumstantial evidence because it is possible to purchase a box of ammo that is identical to the ammo used by a murderer, and a firing pin can strike a primer in the same spot and create an identical primer strike.
So now it can only be used to place someone in the area and added to evidence to tip the scales of justice unlike before when it was used as the only evidence to charge people
>>28332152
Man, I still love that fucking movie.
>>28332166
This is what I thought too
>>28332011
Watch some Forensic Files.
