What is your definition of trespassing? As a non american i would think that trepassing is beeing on someone elses property without permission, not beeing with a violent mob storming a gouvernemnt building with the (at minimum) intent to destroy stuff and breaking the democratic process.

And Rittenhouse was clearly looking for trouble, i don't think a black perosn could Go fully armed to a KKK rally and claim self defense if started shooting people after beeing harassed there.