The zombie outbreak is contained and people survived in fortified cities and on islands and so on.
Humans who die in any way that does not destroy the brain will turn into zombies.
Rules of that is simple: 5-30 minutes until they start changing. Once they start the change they turn within a few seconds.
The biggest problem here is simple: What prevents a person from killing someone, then claiming they died and turned, then the person doing the killing were forced to kill them?
There are many many ways you can kill a person without showing signs of resistance or destroying the brain...etc.
The governments of the setting are exactly like ours.
Can the government in anyway figure out if a person who turned and got killed did in fact die naturally or was killed and then the murdered waited for them to turn to cover it up?
I mean using science or any certain methods not simply investigate the case. Not a 'torture suspects until they confess' sort of solution. Like how DNA testing is scientific
Edit: I'm not suggestion that police work is useless. I'm trying to explore other methods or at least how will the zombie factor change things. Because normal police work is not a mystery I'm not focusing on it as much.
Extra fluff
I'm only interested in can it be done or not. Suggestions outside of this don't seem to fit. Suggestions of put cameras everywhere don't sit will. But I'm not saying don't try to provide a solution, I mean I can't stop anyone, just saying that we are trying to solve a specific problem here.
I also understand that if a person did the killing on camera it's a done deal. This is for situations where no video evidence exists and there is a distinct lack of forensic evidence...etc
Suggestions of: "Police work" will fall apart here.
Sure hating someone might make you a suspect if they died by your hands. But that's not concrete evidence. A couple who fights daily, does not mean that one of them will murder the other!
If a person dies young then that makes it extra suspicious.
True. But since we don't have an exact time and date of the death of people, again a murderer can simply claim they died naturally and turned. Death just happens.
Pass a law to require people to report the deaths immediately.
That's not a terrible idea. But again people can work around it. Like you wake up to your partner shaking violently in the bed. Naturally you picked your pistol and killed them before they can kill you or the kids. But a worthy idea.
Also understand that in the post outbreak cities people carry weapons and are expected to murder zombies on sight. The survival of the block and entire city is more important than anything. So. It would be easy to exploit the system to get away with murder.
Anyway I don't want to bore people with my own ideas and suggestions here. Feel free to agree or disagree as long as it is detailed please.