Re: Star Trek: DTI: Watching The Clock Review Thread
Right. There is no legal justification for arresting someone who has not yet committed a crime. At most, if there were multiple parties involved in planning to commit a crime, you could charge them with
conspiracy even if they haven't acted on it yet.
Certainly if you know a crime is going to happen, you can take steps to prevent it, and perhaps to catch the perpetrator in the act of attempting it. Or you could talk to the future culprit, try to talk them out of it or warn them off. But you couldn't arrest them unless you found evidence that they'd already done something illegal or caught them attempting it. (And that means relative to their own personal timeline. Doing what Ducane did in "Relativity" -- arresting the younger Braxton for something his future self had been caught doing -- is utterly unethical.)
But I think I discussed this upthread -- if you can arrest someone for a future crime, it means you're in a universe where the future is mutable rather than fixed. And in such a universe, you can never be 100% sure that the future in which they committed the crime is certain to occur. It's just one possibility. So you're not arresting them for something you "know" they will do, just for something you believe they might do. And that's not ethically justifiable.
It's also not judicially feasible. How do you prove in a court of law that someone is guilty of a crime you prevented from occurring at all? No crime means no evidence means no case. And evidence of the crime happening in an alternate timeline wouldn't cut it, because the crime didn't happen in the timeline over which the court has jurisdiction, i.e. the one it occupies. Conviction requires proof beyond a reasonable doubt -- any alternative theory of the case must be ruled out, with the defendant's guilt being the only reasonable interpretation of the evidence. If the defendant committed the crime in one timeline but was prevented in another, then built into that is an alternative theory of innocence that can't be disproven, because it's actually what happened in the timeline you occupy. Therefore, obtaining a conviction would be impossible.