As with many films based on true historical events, there have been a few liberties with the film plot. But the character of Frederick Aberline was very much real, and was the lead investigator of the Jack the Ripper murders. I just finished watching "Murder By Decree" a 1979 film on the ripper murder subject with Sherlock Holmes as the protagonist, and many of the critics of that film ran down this movie as be too far fetched, or Aberline as a second rate invention. But in fact Abeline (Johnny Depp) was very real, just as was Robert Lees the noted medium of the 1890's who worked with the police on several cases. I enjoyed "Murder by Decree" for it's style and cast but this film for it's more accurate portrayal of the events of the White Chapel murders. Depp and Coltrrane are excellent and well portrayed with their warts as well as their good qualities. This film stands well on it's own.