What is the evidence that supports the claim that James Kelly was JTR? If you are a rival detective, how do you eliminate all the evidence that you've identified in the documentary?

I had watched “Jack the Ripper in America” and from my research about the case, James Kelly was the JTR. He was sent off to Asylum because he had killed his wife by stabbing her neck and the other five canonical were killed the same way. He had managed to escape from the asylum using old fashioned key in 1988. The murder does not happen when he is in the asylum. That shows he is the JTR obviously. Apart from that, what makes him expert in killing is the expertise of him in as a furniture upholsterer which is good in handling the knives. From my opinion, back then there was no technology that could trace a serial killer, but nowadays, there is lot of technologies that could trace a killer. For me, he is just insane person who is obsessed in killing.