Rittenhouse is a young kid who wanted to help as far as I can tell. He has volunteered for a fire department before, has some sort of EMT training (even if not much), can be seen multiple times on video offering people help or giving help, has been seen cleaning up graffiti left over by protesters. I think his willingness to help is much more clear than going there "with violence on his mind". I can guarantee you this kid idolizes firefighters and policemen, and I actually raise my own sons to be like that.