You don’t know Jack.
I do not believe that George Chapman committed the murders of Jack the Ripper. My main reason in doing so it that his previous victims were killed in totally different ways that those of the prostitutes. Taking into consideration that Chapman killed his victims with poison slowly over time, he must have like to watch his victims die slowly. So therefore I do not think that a killer would change what he enjoys from his killings so drastically. Going from blitz attacks to slow deaths would not give him the same “high”. Chapman would have liked seeing his victims die very quickly and brutally. Poisoning would not give the same effect. I realize that he had a violent history toward women and he had killed before, but that does not account for the fact that he would have changed so much in his killing style. FBI profiles and such would have to be completly wrong for someone to belive that Chapman was the Ripper.