Ms. Spencer mentions having previously reported Mary's disappearance at Leman St. police station, where no one was interested. This was the police station featured in "Ripper Street", a similarly-themed show on the BBC. It was also the headquarters of H Division which investigated the real Jack the Ripper murders.
Unlike the end of this movie, Jack Whicher never left the force. Though his reputation was tarnished by failing to close the case, over the years he built it back up, eventually reaching the rank of assistant superintendent, retiring in 1881 and passing away later that year. Only this first movie is based on a real case: the rest are works of fiction.