I don't know enough about the situation or the trial to comment on him being guilty of murder. I have found the whole affair to be useful way of spotting the nazis in our midst though. Thanks OP.
Before I became interested enough to look up more details of the trial, one of the first things I noticed was the political makeup of the majority of groups and media outlets who were most vocal about supporting Rittenhouse: far-right ideologues such as Ann Coulter and Tucker Carlson, Evangelicals who support theocratic and abusive legislation, and even white supremacists such as the Proud Boys, among others.
Rittenhouse himself might not necessarily share any of these groups' beliefs—and I realize that many of his supporters don't either—but when certain groups often harbor many individuals who have harmful and inaccurate views about the world and various issues of considerable importance, it raises red flags when most of them seem to so strongly agree on supporting someone.