why did Boney even have a sweatshirt at the crime scene?
That question is answered by Boney himself. During his attacks on Indiana University coeds in 1988-89, he often wore disguises. After he was apprehended, he made several stark admissions, including one that he had an “escape plan” (his words). He would wear a sweatshirt to the scene of the crime and then later take it off and place it into his backpack in order to not have on the same clothes as the perpetrator should anyone have seen him. He had an escape plan and Boney’s escape plan was his sweatshirt!