Thomas Bowyer was born c. 1825 in Surrey. He had served in the Indian Army sometime before 1888, and was receiving a pension from them. He lived at 37 Dorset Street, Spitalfields. He worked for John McCarthy, and on the morning of November 9th, 1888 he was sent to collect rent from Mary Jane Kelly, who was several weeks overdue. He was sent sometime between 10 and 10:30 that morning. At first he knocked on the door and, when he received no reply he moved over to the window, which he noted as being broken. He moved the curtains and looked into the room. There, lying on the bed he saw the mutilated body of Kelly. Immediately he fetched McCarthy, who sent Bowyer to the Commercial Street Police Station. He reported the discovery to Inspector Beck, who was on duty there, and then returned to Miller's Court with police officers in tow. Walter Dew, who was in the station when Bowyer arrived, described him as terrified and unable to speak when he first arrived.
Bowyer testified at the inquest into the murder on the 12th, but provided no new details, aside from clarifying which window he had looked in, as well as saying he had only seen Kelly drunk once before. He also stated in a newspaper interview that he had seen Kelly speaking with a man who had "peculiar eyes" on November 7th.
In 1891 he was registered as a pauper in Shoreditch Workhouse. No further documentation of his life exists.