Following his sentencing to Moyamensing, the police learned that Charles Harris, alias Charles Hanlon, was actually John Hanlon, owner of the barbershop next to the site where Mary Mohrman was abducted, and one of the early suspects in the case. They were convinced he was her killer.
and asked if he would share a cell with John Hanlon and secretly report back to them all that Hanlon said to him. Dunn was an Englishman; a career criminal who had been transported to Australia for theft. When his sentenced was finished he came to America where he arrested for theft again. He agreed, and Hanlon was moved to Dunn’s cell.
Trial: October 31, 1870