At about 23:00 on 30 August, Nichols was seen walking the Whitechapel Road; at 00:30 she was seen to leave a pub in Brick Lane, Spitalfields. An hour later she was turned out of 18 Thrawl Street as she was lacking fourpence for a bed, implying by her last recorded words that she would soon earn the money on the street with the help of a new bonnet she had acquired. She was last seen at the corner of Osborn Street and Whitechapel Road, at 02:30, an hour before her death, by Nelly Holland. Nichols claimed she had made enough money to pay for her bed three times over, but had drunk it all away.
At about 3:40, she was found lying on the ground in front of a gated stable entrance in Buck's Row (since renamed Durward Street), Whitechapel, about 150 yards from the London Hospital and 100 yards from Blackwall Buildings, by cart driver Charles Cross. Her skirt was raised. Another passing cart driver on his way to work, Robert Paul, approached and Cross pointed out the body. Cross believed her to be dead, but Paul was uncertain and thought she might be unconscious. They pulled her skirt down to cover her lower body, and went in search of a policeman. They informed PC Jonas Mizen and continued on their way to work. As Mizen was approaching the body, PC John Neil came from the opposite direction on his beat and by flashing his lantern, called a third policeman PC John Thain to the scene. As news of the murder spread, three horse slaughterers from a neighbouring knacker's yard in Winthrop Street, who had been working overnight, came to look at the body. None of the slaughterers, the police officers patrolling nearby streets, or the residents of houses alongside Buck's Row reported hearing or seeing anything suspicious before the discovery of the body.
PC Thain fetched surgeon, Dr Henry Llewellyn, who arrived at 04:00 and decided she had been dead for about 30 minutes. Her throat had been slit twice from left to right and her abdomen mutilated with one deep jagged wound, several incisions across the abdomen, and three or four similar cuts on the right side caused by the same knife at least 6–8 inches (15–20 cm) long used violently and downwards. Llewellyn expressed surprise at the small amount of blood at the crime scene, "about enough to fill two large wine glasses, or half a pint at the most". His comment led to the supposition that Nichols was not killed where her body was found, but the blood from her wounds had soaked into her clothes and hair, and there was little doubt that she had been killed at the crime scene by a swift slash to the throat. Death would have been instantaneous, and the abdominal injuries, which would have taken less than five minutes to perform, were made by the murderer after she was dead. When the body was lifted a "mass of congealed blood", in PC Thain's words, lay beneath the body.