Pretty clear that Oswald didn’t shoot Tippett.
But bolt action rifles are not like handguns as far as the possibility of gunshot residue is concerned. I have not seen a competent study of residue from rifles, but I’d like to see one.
But I have stood in the Schoolbook depository window and looked down at the street. Making that shot is not “easy” but as a longtime deer hunter, I have seen guys make more difficult shots look easy. No question in my mind that an expert rifle shooter could make that shot from that window.
Not proved.