Francis Thompson was an extremist Catholic who apparently wasn't fond of prostitutes, a pyromaniac (apparently Mary Kelly's clothes were found burning in the fire at the crime scene according to a website that I've stupidly managed to lose), an ex-medical student (the women were cut up by someone who had good knowledge of cutting things up), a poet who wrote messed up poems about killing prostitutes by pretending he was performing abortions, if you read the poem he wrote it's almost a confession (also, the Jack The Ripper letters that the police got were well-written and had good hand-writing which must have meant that the guy was educated, right? And they were written in Red ink which would probably be more accessible to someone in the writing business in those days), he KNEW Mary Kelly (he lived at the same freakin' address) and Mary kelly was the odd one out of the victims, in age and the way she was cut up more, the psychological stuff matches him perfectly, apparently he kept a knife in his coat and there's a whole lot more detailed stuff to note.
The only problem is, according to the pictures of him I found, at the time of the murders he didn't really match the witness descriptions.
Oh and I think Mary Kelly is the key to solving the case, especially being the odd one out of the victims. I've got a few conspiracy ideas about her...