Yes, people are fine with all sorts of murders and other atrocities taking place, as long as its not happening to them. As long as the right kind of people suffer. Your phrasing is wrong, of course, because you're conflating support for something with committing the act yourself, but you're not too far off the mark.

If you are present for a murder and you do nothing to either prevent it or report it, then yes, you are complicit in the murder.