Around 20 years ago there was a TV special where they had some of the top retired agents of the world’s best police agencies try to determine who he was.
They included FBI, Interpol etc.
None had studied the case before and all were provided all known info about the case.
At the end each revealed who he had determined was Jack. None had any contact with each other. When they did the reveal, every single one had selected Kosminski.
Portrait of a Killer: Jack the Ripper—Case Closed (ISBN 0-425-19273-3) is a 2002 nonfiction book by crime novelist Patricia Cornwell which presents the theory that Walter Sickert, a British painter, was the 19th-century serial killer known as Jack the Ripper. Jean Overton Fuller, in her 1990 book Sickert and the Ripper Crimes, had maintained that Sickert was Jack the Ripper. Prior to that, Stephen Knight, in his 1976 book Jack the Ripper: The Final Solution, had maintained that Sickert had been forced to be an accomplice of the Ripper.
Guess they were wrong. Or perhaps Sickert was the accomplice of Kosminski. It would be interesting if this was investigated.