I just got my hands on an advance copy of Library of America’s forthcoming “True Crime: An American Anthology,” which I will be writing about at length in the fall. Included is a piece by Jack Webb on one of America’s most famous crimes, the 1947 murder of Elizabeth Short—aka the Black Dahlia—whose whose mutilated body was found in a abandoned lot in LA’s Leimert Park neighborhood. Unsolved to this day, Short’s murder has inspired a lot of crackpot theories about her killer’s identity—someone even fingered Orson Welles as a suspect. Advances in forensic technology have brought us no closer to a solution; the Dahlia killer remains in the shadows, just out of reach, a constant incitement for wild speculation and a lot of factually dubious funny business.

You could say the same thing about one of history’s other elusive killers, Jack the Ripper. Who was he? Everyone from Lewis Carroll to the Duke of Clarence has been named as a suspect. A few years ago, the mystery writer Patricia Cornwell made a complete fool out of herself trying to prove that British painter Walter Sickert was the real Ripper. Not a chance. More recently, in his utterly fascinating book “The Fox and the Flies: The World of Joseph Silver, Racketeer and Psychopath,” the South African historian Charles van Onselen advanced the notion that the Polish-born Silver, a police informant and small-time hood, was the Ripper. Van Onselen doesn’t quite prove his case—much of his evidence is circumstantial—but his research into the late 19th century underworld is staggering. The book didn’t attract much attention, but was the subject of a very fine piece earlier this year by the English writer Charles Nicholl.