Identical twins do not have the same fingerprints.
A tag line for this movie claims the original Jack The Ripper raped his 5 victims. This is not true, none of them were sexually assaulted.
Mary Kelly, the Ripper's final victim, was not pregnant at the time of her murder. It was a popular claim at the time of the movie, but there are no historical documents (autopsy, etc) stating this.
In the fight scene not long after the hooker has been found murdered, it appears the killer has split his pants open at the buttock seam as his white undergarments are visible.