I don't feel the need myself to see any pictures of what remained of his body after the attack, and I rather doubt anyone who is talking about a conspiracy theory would be persuaded by the appearance of any such pictures. Yes, a trial would have been better ... but I can't see how it would have been practical. The security required for incarcerating him and protecting all those involved in the case would have been extraordinary and quite possibly prohibitive; I can't see how you would get jurors who could approach such a case with an open mind; any sort of non-jury based trial would be open to scorn for conspiracy/establishment reasons; and I imagine lawyers would be picking over the legal niceties of the process for years.
I'm not dancing in the streets but I'm not in the slightest bit sympathetic either. I find all the flag-waving in the US a bit distasteful, but then again ... it's really no different to any number of news reports from the Middle East over the years showing more-or-less anti-American/Western crowds all hyped up, so - gasp - maybe on the whole we aren't actually all that different from them after all. (And as many have pointed out, the crowds on the streets in the Middle East in recent times have seemed to be campaigning broadly in favour of Western political systems, rather than demanding the return of the Stone Age).