"The killings on Cape Cod in 1969 were the most vicious serial murders since 'Jack the Ripper' stalked the women of East London back in the 1880s," says Casey Sherman, author of the new book, "Helltown: The Untold Story of a Serial Killer on Cape Cod."
Sherman's book explores the story of serial killer Tony Costa and the horrific murders of four women in the seaside community of Provincetown.
"Sydney Monzon, Susan Perry, Patricia Walsh and Mary Anne Wysocki were shot, stabbed, dismembered and buried in shallow graves all because they placed their trust in a polite, outwardly harmless young man," Sherman says.
He says the case was mostly lost to history because the Manson murders happened around the same time, and it was also right after "the assassinations of RFK and MLK, a raging war in Vietnam and the bloody violence of the Democratic National Convention in Chicago."
Sherman, who grew up on Cape Cod, says he learned about the case "in almost a joking fashion, as serial killer Tony Costa was nicknamed 'Tony Chop Chop' by local residents."
Once he learned about the depravity, though, he pored over more than 2,000 pages of police reports, trial testimony, crime scene and autopsy photos and, he says, "I've never seen anything more outrageously brutal in my nearly 30 years as an investigative journalist."
Sherman is among the most well-known true crime journalists in the United States, co-authoring "Hunting Whitey," the story of the hunt and capture of Boston mobster Whitey Bulger, and co-hosting the podcast "Saints, Sinners, & Serial Killers."
His pull toward crime reporting, he says, is personal: "My aunt, 19-year-old Mary Sullivan, was the youngest and final victim in the notorious Boston Strangler case. I re-investigated the case and wanted to give my aunt Mary a voice that she did not have during the original investigation where she was discussed merely as a crime statistic."
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In "Helltown," the time and place become characters: 1969, for the chaotic reasons mentioned above, and Provincetown, because the outer Cape town is, and always has been, known as a place for artists to be themselves without fear.
There is also a made-for-TV added dimension of truth. At the time of the murders, famous writers Norman Mailer and Kurt Vonnegut were living in Provincetown.
"It was a very rare thing to have two literary icons such as Kurt Vonnegut and Norman Mailer reporting on a serial murder case in their own backyard as both men lived on the Cape at the time. In early 1969, Vonnegut had yet to become a literary star, while Mailer had been a bestselling writer since his debut novel, "The Naked and the Dead," in 1948," says Sherman.
He adds, "In 1969, both writers are confronted with ultimate evil and become obsessed with the ritualistic killings in their community and are drawn to the killer himself -- Tony Costa."
In the book, Sherman uses his knowledge and digs into the murders from Costa's viewpoint. "I got access to an unpublished manuscript that serial killer Tony Costa had written before he committed suicide at Walpole State Prison in 1974. In it, he describes the murders in vivid detail through an alter ego that he had created for himself," Sherman says.
"Helltown" is already set to be made into a limited series in conjunction with Robert Downey Jr.'s production company, Team Downey. Sherman's other books have translated well to screen, including "The Finest Hours" and "Patriots Day."
Up next for Sherman? A book on the incredible movie star Lana Turner.