Patricia Cornwell knew practically nothing about Jack the Ripper before being invited on a tour of Scotland Yard. She says she didn't even know how his victims died or that they were prostitutes. Her interest was in using him in a Scarpetta novel. When she asked Deputy Assistant Commissioner John Grieve if anyone had ever tried to use modern forensics methods to solve the murders, Grieve mentions artist Walter Sickert, who painted a picture entitled "Jack the Ripper's Bedroom." Rather than examine the evidence, consider the various suspects, and seize upon the most likely killer, Cornwell is immediately hooked on Sickert.
Sickert is as good a choice as any, actually, at least as good as Montague Druitt, the Duke of Clarence, physician John Gill, or Aaron Kosminski. What bothers me most is Cornwell's blatant hubris. It's been a hundred and fourteen years since the murders; yet, she knows better than the fumbling detectives who worked during the original time frame, one of whom (Sir Melville MacNaghten) had the audacity to write a book about the murders, choosing Kosminski as his Ripper.
Cornwell's chosen structure is also aggravating. She spurns a preface or introduction, which would have given her a chance to explain how she came about writing the book in her own voice. Instead, she interrupts the narrative flow, consistently interrupting to explain her superior forensic technique. So, what does she come up with? Sickert was sexually impotent, having had three operations on his penis prior to age six, possibly without anesthetics. She loves that word "possibly", also "maybe" as well as the words "could have." As a result of the painful operations, Sickert hated women. This despite the fact that he was married three times. "Possibly," he married them for money or "maybe" because he needed a mother figure. What else? Sickert loved attention; he wrote hundreds of letters and articles for the newspapers. Thanks to Cornwell's legion of researchers, she finds watermarks on the Ripper's letters that match Sickert's stationery. She also decides that most of the Ripper letters were genuine. The authorities were hoaxed by the different handwriting, and Sickert, being an artist, could imitate many different styles.
Another aspect of the letters she finds incriminating is the Rippers's persistent use of "Ha! Ha!" Once again that points at Sickert, whose mentor James McNeil Whistler was notorious for that annoying laugh.
One wonders how Cornwell can look herself in the mirror when she implies Macnaghten wrote his book for money. Listen to this drivel: "`I hate this book, Ester (her agent). . . .' I was losing my life to Walter Richard Sickert. He was taking it away from me. `I want to write my novels,' I said. `I don't want to write about him. There's no joy in this.'"
There's not much joy in reading the results either. A better bet is to check out casebook.org to see what the Ripper fanatics do to Cornwell.

Dave Schwinghammer's unconventional mystery, SOLDIER'S GAP, available on authorsden and at Amazon.com, new and used, is almost as grisly in spots as the Ripper's work, but there's also humor and an underlying meaning, countering the nasty stuff.