I was playing GTA4 and was thinking about how cool it would be to have a team of detectives following your case, and if you happen to find out who they are, killing them before they find you out, or somehow else being able to steal evidence. Perhaps somewhere down the line with the whole multicity police thing something like this could be implemented (say, police stations having evidence lockers you can clear out, reducing heat in that city, maybe making some low-level criminal charges disappear, or having to hack the computer system in the Intelligence HQ to get a massive heat drop nationwide as well as purging a good few crimes from your record)
Here's what I think- It takes a while for dicks to build up a case against you. Tampering with evidence or discovering witnesses allows you to, later on, be much more succesful at trial. (there's no good way of getting out of 500+kills).
Even better- The cops may not be able to put it all together. Cops in Atlanta may not know you have outstanding crimes in Seattle, and you potentially won't be tried for them. This all becomes less relevant once LCS becomes well known- then the crimes stand a better chance of being connected. The FBI getting involved is worse news, since that's essentially their job. And the CIA can't really be messed with since they'll just trump up charges or blame CCS events on the LCS, and do false flag OPs.
So it would be neat if your crimes were potentially untraceable (disguise skill?), or you could screw with witnesses/juries/evidence by several means (hacking, infiltration, well placed sleepers), and potentially sabotage cases by murdering or converting detectives, once they get discovered. And if different agencies had their own lists of evidence/witnesses and detectives associated with certain crimes, that'd be cool too.
That all sounds like a beast to implement, so I'd say skip it.
Gun laws are federal, I believe. It would be just as hard to buy guns legally in South Alabama as it would be in downtown New York. Illegally, on the other hand...
There are state gun laws and federal gun laws.
Example: Weapons of caliber .50 inches (across the lands of the rifling, .50bmg is actually .510 inches) are legal to own federally. Many states do not legislate on this. HOWEVER, in california, there is a .50 caliber ban (which resulted in a more effective caliber, .416 Barrett... go figure). So it would be difficult to get a .50 AE Desert Eagle or a 50BMG rifle or a 50BMG M2, etc. in California, but no problem in Arizona.
Example2: Suppressors (silencers) are federally legal, but registered, with a 200 dollar tax on transaction. The process takes a few months. However, Montana and other states ban suppressors. (OK montana is weird, but for all intents and purposes they're banned.)
Example3: similar to suppressors, automatic weapons (Known legally as machine guns) are federally legal, but registered, with a 200 dollar tax on transaction. The process takes a few months. HOWEVER, the state of Washington bans possession of automatic weapons. One could not legally own one there, and in a few other states.
Example4: New York, California and other states have magazine limits. It is illegal to own magazines above some arbitrary number in these states.
Example5: New Jersey and other states ban quite a few firearms by name. Those would be illegal to own in their respective states.
Example6: Colorado used to be lax on gun laws. Denver, CO, however, had an "assault" weapons ban for a long time.
In short: Gun laws exist at the Federal, State, AND LOCAL level...
Maybe events in one state result in a stronger local push for state Guncontrol laws first, resulting in cities lowering gun availability before the country?