On 13 February 1891 Police Constable Ernest Thompson was patrolling alone for the first time since he joined the Metropolitan Police.  At 02:15 he heard the footsteps of a man retreating and then his lamp shone upon the body of a woman in Swallow Gardens. She was still alive. Instead of chasing the man Thompson obeyed the rules and tried to help the victim. Sadly, Frances Coles could not be saved. Her murder is included in the police files on Jack the Ripper, but it is not generally accepted that he was responsible.

The police arrested Thomas Sadler. He was cleared at the inquest, not least because he was severely drunk at the time of the death and unable to have inflicted the wounds. Sir Melville Macnaghten, who assigned five victims only to Jack the Ripper, continued to believe that Sadler murdered Francis Coles. We know that Sadler was not Jack the Ripper as he was at sea during the previous crimes.

Ernest Thompson often wondered if he could have caught Jack the Ripper. He continued to patrol the area until December 1900 when he was stabbed to death whilst on duty. He left a wife and four children, all aged under four.