Real-world criminal science questions.

[khorboth]

For brass, your better bet may be going the other way - get some extra brass either from a range or from some other source and scatter it. That may quickly overwhelm the resources the investigators are willing to put into this. Just be careful you aren't giving an extra vector to find you by always buying used brass from the same place.

Not to derail the thread, but this gunshot detector is real and also hard to defeat.

[Flyndaran]

That could bite them on the butt years later when the department finally gets around to processing all the remains.
But limited budgets for settings not too heavily based on fiction like C.S.I. is somethiin to keep in mind.

[Anthony]

It's worth remembering that IDing a gun by either bullet marks or marks on the casing only tells you that it's the same as another gun you have forensic information for, and if the gun has not previously been used illegally it probably won't be in a database.

What this means is that, without switching barrels and so on, it will help them figure out that two PC-related crime scenes are both the same set of criminals, but probably isn't directly valuable in IDing the PCs; if the police are at the stage of executing a search warrant for guns matching those forensics they are already pretty darn certain of their target and the forensics is more 'another nail in the coffin' than necessary evidence. Also, typical PC behavior is distinctive enough that it's not likely the police will need forensic analysis to conclude "probably the same group".

[Fred Brackin]

Originally Posted by acrosome

T
Anyone have other clever ideas for confounding the fuzz?

From a real trial, a woman was shot from a distance of about 20 yards (from across a cul-de-sac in a housing development) with some sort of jacketed soft point bullet from an at least medium-powered rifle.

All HP bullets are at least somewhat velocity sensitive and this rifle bullet had probably been designed to expand properly at the velocites resulting from impact at 100 yards and over. At 20 yards it was way over optimum velocity and the jacket separated from the lead core and turned into metal confetti. The lead core deformed and lost at least some weight as it passed through the body and then exited the body and buried itself in the back wall of a garage and of course deforming some more.

On TV a genius forensics tech would have recontructed the jacket with an amzing computer and gotten the rifling marks that way but this happened in the real world. The police were unable to tell what the caliber of the rifle was or the weight of the bullet. Even that it was a very common civilian type of bolt-acton hunting rifle was only an educated guess.

I have not heard how much Fackler-type fragmentation of military-type bullets at short range effects identification techniques but crimes in the US with such bullets are quite rare but the effect can't be good. As Dr. Fackler will explain, when the bullet begins to tumble it will break apart at the cannelure with the entire rear half of the bullet fragmenting. I would expect that rear half to be where most of even all the engraving marks to be.

There are of course caveats such as "Don't use those iron-cored AK-47 bullets!" or any other type that might survive tumbling. On the other hand there are frangible bullets such as are used for varmint hunting. Lots of luck reconstructing them. Persons attempting to use those in a full auto rifle are requested to delay their experiments until I can retire to a safe distance but it might well work.

I think rifling matching is a thing that works best with minimally deforming pistol bullets that aren't much seen any more. A lot of forensics tech gets overestimated for purposes of fiction. At the least it's a case of counting the hits and ignoring the misses. I wouldn't worry a lot about military-style stuff at close range.

[Polydamas]

Kromm's The Company campaign on his Livejournal and Icelander's various campaigns on this forum have worked examples of this, one of them by a defence lawyer, the other by someone who has lived in sketchy parts of Montreal.

As others have said, probably the most important thing is how much attention the police give the crime. If a shooting or stabbing looks like just another gang killing, it may not get close attention, if it gets into the national media then it will get a full forensic treatment. And a world with bullet-spraying monster hunters chasing werewolves would look different than ours, a lot more like parts of Mexico or oughties Iraq than Germany or Japan.

[Ulzgoroth]

From what I've seen about the 'forensic science' of ballistic matching, it's not really a thing even for regular single-shot loads. An expert witness might be willing to testify that it is, and investigators might even believe it, but the actual results are pretty arbitrary. So the question is more 'will the forensics guy be inclined to find this as a match' than 'did the bullet actually come from this gun'.

That's for the supposed matching of recovered bullets to a specific firing gun. Identifying the caliber and type of the recovered bullets probably works just fine, so as Anthony said if you're using something weird an investigation will probably notice that.

[Polkageist]

I'd really like to have the time to dig up crime statistics, so I might be wrong here, but I seem to recall that a majority of murder-type crimes are solved by digging into the relationships of the victim and the circumstances of the death in order to discover the criminal, and the various bits of physical evidence are used to confirm or reinforce the case against them.

So, aside from personally identifying stuff like DNA, just leaving litter around won't be enough to get them caught. It'll damn them if they're caught later on for another reason, but as someone said above the investigators will really only be able to tell that the same gun did this or the like. Since monster hunters typically aren't shooting baddies who they personally know, in their usual hangouts, around witnesses, cops would probably be just as well off picking names at random out of a phone book. As long as the players aren't being explicitly careless, I'd probably give them a pass.

That said, putting investigators on their tails is an excellent way to remind players that they're causing too much collateral damage. Burn Notice has a really fun side-plot of a cop who starts to get curious about all the explosions and such happening around Miami and starts following Michael Westin around to try to actually get enough evidence to catch the guy that's leaving massive amounts of property damage and the occasional dead goon lying around. She never does, because Michael takes reasonable precautions, but it shows that you can have the cops snooping around and being part of the story without them shutting down the game by arresting people outright. Roleplaying Law & Order is... probably not everyone's cup of tea. I've often just charged the players some cash or resources for 'legal fees' to make the problem go away because we have better things to do than RP a deposition.

So there's a nice sliding scale of attention that you can use, going from hearing sirens earlier than expected, to seeing notices going out in papers and such (great reason to have a contact and/or ally in the local PD!), to having a cruiser parked outside their house.

Then you don't have to worry about what evidence exactly the police are collecting (they've got SOMETHING), just that the players have been careless or overly aggressive in their monster hunting work justifying ramping up police attention. Then, if/when the players start taking precautions (black-market equipment, disguises, better choice of fight location) you can slack it off.

[Anthony]

Originally Posted by Polkageist

I'd really like to have the time to dig up crime statistics, so I might be wrong here, but I seem to recall that a majority of murder-type crimes are solved by digging into the relationships of the victim and the circumstances of the death in order to discover the criminal, and the various bits of physical evidence are used to confirm or reinforce the case against them.

That has to do with what the typical homicide is; monster hunters are probably more like particularly violent armed robbers than ordinary homicides.

As a side issue, any serious investigation of monster hunters would spend effort on figuring out the connection between those crimes, which would tend to reveal 'oh, monsters'. If monsters are a secret in this universe, which is normal for MH, it's likely that whatever protects the monsters from detection will also protect the hunters from ordinary police attention, though not from whatever is protecting the monsters.

[Polkageist]

Armed robbers that are robbing abandoned warehouses for some reason.

You're right, I think that the weirdness around monsters kinda keeps a focused investigation at bay. Cops would be looking for a human being, so a werewolf that's killing people just isn't something they'd think to look for, supernatural protection or not. Similarly, police probably won't put much effort into finding whoever shot up that old house, plus what's with that weird pile of ash in the middle of the room? Damn vandals probably had a campfire or something.

Now, breaking things that aren't directly monster related, that'd bring some heat.

[Apollonian]

Originally Posted by Polkageist

Now, breaking things that aren't directly monster related, that'd bring some heat.

Speaking of heat, borrowing the heat mechanic from Night's Black Agents is a handy way of simulating this.