I will briefly explain why I believe that Tumblety could have been the Ripper.
Firstly he disliked women generally, and had a hatred for prostitues, hardly proof of him being a serial killer I know, but he found out his wife had been a prostitute at one time. Tumblety was also in London on the dates the women were murdered, and is believed to be the Batty Street lodger who was staying in very close proximity to the murder locations. He also had medical knowledge, and apart from the butchering of Mary Kelly, it is clear whoever did it had some medical knowledge. The murders also ceased after he fled London, going via France and using a number of aliases. Why would he have done that unless he had great need to avoid being caught by the Police. Scotland Yard contacted New York police for a sample of Tumblety's handwriting, this would have been after the fake ripper letter.
So to my mind there are several things that point to Tumblety being the ripper, but the two main reasons are:
The Littlechild Letter and after his death, the authorities found in Tumblety's possession two cheap, imitation rings. All his other jewellery was expensive, so why have two cheap rings which were identical to ones owned by Annie Chapman.
I rest my case your honour, and eagerly await Mr Jelly's response.