|This article needs additional citations for verification. (May 2008)|
Schwartz told police that, shortly after midnight on September 30, he was walking down a street when he saw a man stop and speak to a woman who was standing in a gateway. Schwartz stated that the man then threw the woman to the ground. Schwartz crossed the street and began walking away when the attacker saw him. The attacker called out the name "Lipski" — apparently an Anti-Semitic insult related to Israel Lipski's murder of a woman the year before. Schwartz reported seeing a man smoking a pipe nearby at the time, and the other man started walking towards Schwartz, possibly following him. Schwartz ran away.
Shortly after the time Schwartz reported witnessing this incident, the body of Elizabeth Stride was found in the same location. That same day Schwartz identified Stride's body as that of the woman he had seen attacked and gave testimony to the police about what he had seen. He was able to give descriptions of both men but was unable to say whether they knew each other or had been working together.
Several years after the crimes, Commissioner Robert Anderson claimed in his autobiography The Lighter Side of My Official Life that the Ripper had been identified by "the only person who ever had a good view of the murderer." Chief Inspector Donald Swanson, in marginalia found in his personal copy of Anderson's book, stated that the witness in question was Jewish. Some Ripperologists have concluded that Schwartz was most likely the man being referred to, although a number of other people, primarily Joseph Lawende, have been suggested as well. Some authors dispute Anderson's claims of there having been a witness who identified the Ripper as being a self-serving distortion of events to try to cover up Scotland Yard's failure to catch the killer.
Anderson's assertion that a Jewish witness identified a Jewish suspect can hardly be true. Schwartz was sent on his way with the anti-Semitic insult "Lipski", which suggests that the man he saw attacking Stride was an anti-Jewish gentile. Lawende, the only other Jewish witness, told Swanson that he doubted if he would again recognise the man he saw with a woman who might have been Catharine Eddowes, ten minutes before her body was found. Swanson (in his "marginalia") said that Anderson's suspect was identified in secret at a police convalescent home that he referred to as "the seaside home" and he named him as "Kosminski", thought to be Aaron Kosminski. He said that Kosminski was taken back to his brother's home in Whitechapel but kept under surveillance until he was taken to a workhouse infirmary, from which he was quickly sent on to the Colney Hatch asylum. Records of the Mile End Old Town workhouse infirmary showed that Kosminski was taken there and transferred to Colney Hatch in February 1891. That was over two clear years from Lawende's sighting of the man with Eddowes and if Lawende doubted then that he would recognise that man if he saw him again, he was hardly likely to have "unhesitatingly have identified him the moment he was confronted with him" as Anderson said in his book.
A minority of authors on the topic have argued that Schwartz's testimony is questionable, as a number of other witnesses reported being in the same general area at the time and did not mention seeing anyone attacked or hear any shouting.