When a law enforcement entity is involved in a shooting, or other incident where a serious injury or death is a result, the investigation is conducted by another entity. In the case of a local LEO, it is usually turned over to the State Police, in the case of the State Police, maybe a large local agency will take the lead, or the FBI, and in the case of ICE, or DHS, probably the FBI, or Secret Service, or maybe even the State Police. You stated the investigation would be conducted by the agent that did the shooting, and that will definitely not be the case. Now you may not trust the other fed agencies (FBI, Secret Service, etc.) right now (I expect you trusted them when Biden was in the WH), but that is how investigations are conducted.
Rittenhouse was not actively protesting, but was attacked while attempting to protect a property from the unhinged extreme fascist left that don't care who they hurt or what property they destroy (is that a Constitutional right?) when he was attacked. Clearly self defense. As to the current situation, I have been out-of-touch for a bit and am catching up, so who knows right now. I am not going to call it murder like you at this point. Maybe it was, maybe not, but much like the case of the driver that actually positioned her car to put the agent in front of it giving that agent less than seconds to make a decision, I will let cooler heads prevail and the chips will fall where they fall.
You do know there is a reason for a little more activity in Minnesota right? I guess you are fine with massive taxpayer fraud enabled by the state official? Should that be just let go?