I have a hypothetical question that I've always wondered

>>33209793
Probably not that much, seeing as their fingerprints would be over all of the brass.

Assuming the criminal managed to pick that all up without putting their fingerprints or DNA on the shells, then it depends on other factors. I assume that there's only one person being killed, and the criminal is using only one weapon, then there's not going to be much between the cops and the killer - if it's a 9mm, it obviously didn't come from any of the rifle-calibur cartriges lying about.

IDK, seems like less trouble to just collect the brass at the scene instead of scattering more.

I know that the "oh we found a bullet let's match it to the gun" meme is pretty objectively false - if they don't have a shell they got jack-all to go on, as most things deform when they hit bone at high speeds.

>>33209793
well honestly i cant imagine majority of the investigation is based on brass, but the caliber of projectile recovered, the unique rifling left on the projectile, possible suspects, eye witnesses , cctv surveillance footage, possible dna left behind, stuff like that, brass just tells me what calliber, and the primer strike may speak to if it was striker fired like how a glock leaves a certain impression on the primer vs a round pin.


but not really knowing anything about how law enforcement does their job, idk man probably wont do shit but piss them off so they add additional charges when they inevitably catch the guy who did the crime.

ALL OF IT.
Just to let them now how newfaggish they are at this.

"He's toying with us, Sir."

>>33209793
Not much. Ballistics/forensics is used much more sparsely than on TV.

>>33209928
Plus the real world uses are most frequently using brass comparisons or slug testing to pile on evidence against the suspects (as in, the person they already suspect without ballistics). Precious few cases when ballistics or brass examinations actually lead to a previously unknown suspect, and usually those are actually cases of ballistics exonerating a primary suspect and forcing investigators to refocus.

>>33209902
>the unique rifling left on the projectile,
Smooth bore revolver

>>33211630
>pretending no markings isnt a unique marking

>>33211630
see:
>>33212539

If they find a custom smoothbore revolver in your car and a guy with a hole in him made by what appears to be a 38 special with no rifling marks, that's not going to look too good in court for you.

If you shoot a guy with a hi-point in the swarthier parts of chicago, however, even if they do find you have a hi-point, it's not strong evidence of anything but your awful taste.

>>33209793
As long as caliber matched what they pulled out of vic they would waste time. Especially if recovered brass had finger prints they could match. Might add some FUD to defense. Any mismatch of brass and they would figure it's a spoiling tactic. Probably not much though. Old mismatched brass and they would probably match prints on what they could and rely on other evidence.

Those crime scene investigation shows do not even have enough time in the episode for the damn paperwork in real life.

>>33209793
it'd only work with various .32 calibers and 9mm/.38

On a related note, and to hijack OP's thread:

I've always wondered just how useful and accurate it is to ballistically match bullets with the rifling that fired them - is the rifling pattern marked in a bullet really as unique as a fingerprint?

Furthermore, how would it be any use to the investigating party if they don't already know the ballistic 'profile' of the shooter's gun? If the gun has a barrel that can be removed without going to a gunsmith, wouldn't it be possible to simply swap one barrel for another and toss the old one in the trash, thus erasing that particular piece of evidence?

>>33214910
I'm actually interested in this as well.

>>33214910>>33214926

>is the rifling pattern marked in a bullet really as unique as a fingerprint?

no it's worthless TV/Hollywood level crap mostly.

>fire a shot
>study ballistic markings
>clean gun
>fire a shot
>gun has completely new ballistic markings

literally that easy.
it's interesting from an academic interest but i can't see much real-world cases being solved that way.
not to mention the bullets misinforming on impact.

>>33214947
>no it's worthless TV/Hollywood level crap mostly.
This doesn't surprise me, yeah. I'd always thought it was nonsense how they'd be able to figure out the rifling marks if the bullet had expanded or fragmented, too.

>>33214910
From my limited knowledge of ballistic forensics, rifling is unique to a rifle. The differences are microscopic, but it's there.

Now, if you could swap the barrel of your gun, like on an AR, then that would just mean that you have an AR and the shooter has an AR, but the two guns don't match ballistically. Prosecutors will have to rely on other evidence to convict, which there probably will be.

I've also seen this thread make mention of bullets breaking apart on impact. This is a friendly reminder that if a piece of the jacket with rifling marks is left in whatever's shot, it can be studied for ballistics. Convictions have been made on this.

>>33209902
im pretty sure the "unique rifling" on the round is just a meme, and on modern firearms can only link it to a certain model, not the specific firearm, unless that firearm has rifling anomalies. if the barrel was made using older manufacturing techniques then it would have "unique rifling" because the mandrill that the barrel was made on is slightly deformed after making each barrel

>>33209902
>cctv surveillance footage
This is how the majority of crime get's solved these days. If inclined to do so (which for most low profile cases they're not because of politics and resource management) investigators can trace even a masked suspect back to a starting point where his face is clearly visible in CCTV footage in most large cities.

>DNA from a flake of dandruff
>rifling
>ENHANCE!
CSI is not indicative of modern criminology, just so you know.

Also, as someone mentioned, it's far easier and more efficient to pick up the brass afterwards, than to go through all the retarded shenanigans OP described.

>>33214972
What if you shoot, collect your casing, then go home and force your barrel to rust, then scrub all of the rust out? Wouldn't that change the pattern?

I was watching this TV show about murder investigations, and they seemed pretty annoyed once when somebody picked up the casings. The next steps they took were usually to identify the victim from their wallet, and contact people in their phone. Then they would analyzing the victims skin and belongings.

I think if you avoided cameras/witnesses seeing your face or car, put on some gloves, picked up the casings, and also grabbed the victims phone and wallet you would set the police back a good bit. But that's all shit I gathered from a TV show.