A few gripes
I watched this the other day and noticed the characters were calling the killer 'Jack the Ripper' BEFORE the letter (from which the nickname originated) had been sent/received.
Also, when is Hollywood going to learn that cockney people don't pronounce every 'T'. Hearing Johnny Depp saying things like "Yes, iT is imporTanT", over emphasising all those bloody T's is so annoying. Then again that mockney muppet Jason Statham has been doing it for years.
Above all though it got me thinking about the case, the mystery of it all and just how far we've come. If the Ripper was around and killing today, to catch him all the police would have to do is look under R in a telephone directory.