If Rittenhouse "goes free" that will be very unfortunate, for him. There are millions of people willing to dole out justice for him, if justice is denied. You need massive security for life to survive that sort of thing, and I doubt he has the resources. He's made himself infamous by his own actions, and somebody (probably many somebodies) will decide to make a name for themselves by being the assassin of Kyle Rittenhouse.
