Factual error: Towards the end of the movie, Mary sends a hand-written note to Inspector Abberline. The 'r' in her name is written in a North American style, where she is European.
Factual error: The scene including the appearance of Joseph Merrick is not correct. The scene shows us Frederick Treves presenting John Merrick to the other doctors. He calls Merrick 'Joseph', but someone corrects him that he should call him 'John'. That is not correct: in real life Treves was the only one who instantly called him John, while his real name is Joseph.
Factual error: The first time you see the Royal London Hospital, the sign says "The Royal London Hospital". In fact, the hospital has only been known by this name since 1990. Before that, and certainly in 1888, it was called The London Hospital. Many people in the East End of London still refer to the hospital as "The London".
Factual error: In the gallery, Prince Albert's portrait has his title as "Duke of Clarence". The movie is set in 1888 and he did not receive this title until 1891.
Answer: As the Ripper was never caught and interrogated, it can never be said with absolute certainty that Kelly was one of his victims. Her death does, however, fit the pattern of Ripper murders quite well with regard to time, general location, methodology and class of victim. There was also a noted trend of increasing levels of mutilation as the murders went on, so, while the damage was considerably more extensive that the previous killings, that also fits with a noted trend of the Ripper murder - it's also worth considering that, as Kelly was apparently his final kill, he may well have wanted to sign off with a particularly grand statement, hence the extreme level of mutilation to the body. This would also explain why the attack uncharacteristically took place indoors - what Jack had in mind for Kelly would take a considerable period of undisturbed time, more than could be guaranteed in an on-street attack. It's also believed that Jack had been interrupted during the murder of Elizabeth Stride on his previous night of violence some weeks earlier - this could also have led him to alter his modus operandi to ensure that this would not be repeated. So, no, it cannot be stated categorically that Kelly was a victim of Jack the Ripper, however the evidence suggests a high probability that this was the case, enough so that many people consider this to be a fact.
Tailkinker ★
It wasn't Mary Jane Kelly.
The question pertained to the real-life Ripper murders, not what we see in this film. It was indeed Mary Kelly in real life.
Phaneron ★