Each murder thought to have been performed by Jack the Ripper took place on a holiday or on a weekend day. This may tell us that the Ripper had a full-time job. Furthermore, altough debated, the Ripper seemed to have somewhat of an understanding of human anatomy, seeing as a lot of people at the time stated that each cut was performed by someone who seemed to know what they were doing.

Additionally, the way the Ripper killed the women was needlessly ferocious; Almost all of them recieved major cuts and mutilations, with some of them having some of their organs removed, and occasionally missing entirely.

One could draw the conclusion that the Ripper seemed to dislike prostitutes, considering they were the victims of the Ripper. With all of this in mind, we can look at a few suspects, the most likely of which to be the Ripper being Francis Tumblety.

I say this because of two reasons:

1. Tumblety's misogyny
2. Tumblety's alleged collection of uteri

Furthermore, the "mocking" tone of the letters (which you can look at here) does seem like how Tumblety would've himself talked and/or written in.

Additionally, multiple witnesses who saw each of the victims before their deaths stated that the victims were with a 'well-dressed man'. This is important because in one photo of Tumblety, he is seen wearing some quite eccentric clothing.

So, I'd say we have ourselves quite the suspect.