I think with the right "spin" these could be very approriate for a courthouse - they show how terrible things have been done in the name of law and/or justice. They show how our judgement can be swayed be our peers and that the way we judge things now will in time be judged by others.

I don't think anyone is endorsing the behaviour depicted - so why the problem? They show something that happened, and reflect a past time with (relative) accuracy. Does removing them make it have not happened, or does it simply allow us to not have to remember? Would these paintings be OK if they'd been produced by and American Indian artist?