And if he does murder someone else? And if he is a war criminal? I wouldn't be able to live with myself if I knew and didn't say anything and someone else's life was ruined/ended. The police would investigate. If they didn't find any supporting evidence, they're not going to arrest him because of one anonymous call.
Knew what? Nobody here knows anything. All anybody (including Dazi herself) "knows" is that the house gives her a creepy feeling and that she believes she heard a voice telling her this particular man is a war criminal. That is not evidence. That is not even a hunch. It certainly does not give anybody any kind of "knowledge" about this man or his past. It definitely
doesn't give enough information to warrant jumping to the wild "ZOMG, WAR CRIMINAL, MASS MURDERER, DANGER!!!!!" assumptions that are being made about this guy, much less provide enough information to merit a call to the police. Dazi hasn't even spoken to him- for all she "knows," he isn't even from the Congo. The only concrete knowledge anybody here possesses is that he's a dark-complexioned man who is new in town. Seriously, you cannot accuse somebody of a crime (especially a serious one, like being a war criminal) on the basis of anything in this discussion. You just can't. Doing so- even suggesting
doing so- is wildly irresponsible. Honestly, how would that conversation even go? "Yes, I suspect that the man living at X address is a war criminal, or at least, that he killed some people over a decade ago during the civil war in the Congo. Why? Oh, a ghost hijacked my iPod and told me." They're not going to take that seriously.