Oscar Isaac may star in Amazon TV series about 1960s Cape Cod killer. What we know.

Oscar-winning director Edward Berger is about to begin production on the fact-based story of a Cape Cod man who went on a killing spree in the late 1960s.

Berger, whose film “All Quiet on the Western Front” recently won four Oscars, including best International Feature, is adapting the book "Helltown: The Untold Story of a Serial Killer on Cape Cod," written by Marshfield resident Casey Sherman, for Amazon Studios. The book was released in July.

“The television series has been a long-time coming,” Sherman said. “I sold the rights to the story before I had even finished writing the book.”

Mohamad El Masri (“Severance”) is writing the eight, hour-long episodes for Robert Downey Jr.'s production company. Oscar Isaac (“Moon Knight”) is in discussions to play the key role of author Kurt Vonnegut, according to a March 13 Variety story.

Sherman said he is an executive producer for "Helltown," a position that is new for him.

The book is about the killings of young women in the late 1960s in Provincetown and Truro.

The book, Sherman’s 15th, chronicles the killings in which at least four young women were dismembered in Provincetown and Truro in 1969. The slayings caught the attention of Vonnegut, at the time a struggling novelist living in Barnstable with his wife and five children.

The convicted killer, Tony Costa, is described by Sherman as “a Manson-type character” who was a “charismatic … god-like figure.”

After a trial that began in Barnstable on May 12, 1970, Costa was found guilty on two charges of first-degree murder and sentenced to life in prison. In 1974, Costa hanged himself in his prison cell.

His ex-wife and generations of the family remain in the Provincetown area. Advocates for the family expressed dismay at the publication of two books in 2022 related to the Costa killings. That displeasure appeared to have contributed to the cancellation during the summer of two book signings at a book store in Provincetown including one with Sherman for "Helltown."

Costa was not an easy subject for Sherman.

“He lured young women into the woods, beheaded them and buried them in shallow graves,” Sherman said. “This book took a lot out of me. My wife would make me take a break for a few days, or a week. It invaded my dreams.”

In an interview with the Cape Cod Times, Sherman said it was particularly difficult living with a pile of crime scene photos while writing "Helltown."

"You live with the material day and night," he said. "If it doesn’t affect you, you're not human."

Sherman said "Helltown" also included insight from Costa's own book, "Resurrection," written while he was incarcerated at what was then Walpole State Prison.

"Costa got three copies of the typed manuscript out. In his manuscript, he blamed the murders on a fictitious person who was really his alter ego," Sherman said. "He came to the end of the line where he realized the person he created in his head was himself. He thought of himself as a struggling author like Vonnegut."

Famed writer Kurt Vonnegut is at the center of the story.

The manhunt unfolds through the eyes of Vonnegut. Sherman said Vonnegut was selling Saabs on Route 6A while struggling with writer’s block during the penning of “Slaughterhouse-Five.” Vonnegut became obsessed with the hunt for the killer and even formed a dangerous bond with Costa, who became known to some as “Tony Chop-Chop.”

“Vonnegut’s daughter knew the killer,” Sherman said. “She migrated with that hippie culture in Provincetown that would later adore Kurt.”

Sherman said Cape residents were shocked by the “barbaric” nature of the killings occurring in such an idyllic seaside setting.

“Kurt was a POW in Dresden, and he has seen war horrors,” Sherman said. “Now he’s seeing it in his own backyard. He used his background as a crime reporter in Chicago in the late ’40s, early ’50s, and put those skills to work.”

Filming of the series may occur on Cape Cod

Sherman said the production team hopes to film the series on the Cape.

“Provincetown is very much its own character in this story and it would be hard to film anywhere else,” Sherman said.

In addition to best International Feature, “All Quiet on the Western Front” won Oscars for cinematography, production design and score. The film, a remake of Lewis Milestone’s 1930 anti-war epic, is a haunting depiction of life and death in the World War I trenches. It can be streamed on Netflix.

Sherman is a veteran investigative reporter and a former WBZ-TV news producer. He also wrote the Coast Guard rescue drama, "The Finest Hours," which was adapted into a film starring Chris Pine and Casey Affleck. It was filmed in Quincy, Norwell and on the Cape. Sherman’s book “Patriots Day,” about the Boston Marathon bombing, was made into a movie with Mark Wahlberg.

Sherman and co-writer Dave Wedge of Milton also penned "Ice Bucket Challenge: Pete Frates and the Fight Against ALS"; "12: The Inside Story of Tom Brady's Fight for Redemption," about the New England Patriots Deflategate scandal; and "Hunting Whitey," a chronicle of the pursuit and capture of infamous crime boss James J. “Whitey” Bulger.

"Hunting Whitey" has been adapted as a stage play and is scheduled for a one-night, sold-out performance on May 16 at The Wilbur in Boston. Actor Neal McDonough ("9-1-1: Lone Star," "Yellowstone," "Band of Brothers"), a Barnstable High School graduate and longtime friend of Sherman's, will play Whitey Bulger.

"Watching him transform into Whitey Bulger is thrilling and frightening to see," said Sherman, adding that the stage show is rehearsing via Zoom with a run limited to one night because of McDonough's filming schedule for other projects. But "Hunting Whitey" may have a reprise, Sherman said, if McDonough's schedule eases.

In 2003, Sherman published his first — and most personal — book, "A Rose for Mary: The Hunt for the Real Boston Strangler."

The book tells the story of Sherman's search for the man who killed his aunt, Mary Sullivan. She is believed to be the Boston Strangler's 13th and last victim. Much of Sherman’s research in deconstructing the single-killer myth was the basis for “Boston Strangler,” which began streaming on Hulu last week. In it, convicted murderer George Nassar is alleged to have also participated in the killing spree.

“They basically took the second half of my book and gave it to Keira Knightley’s character,” Sherman said. “I exposed inaccuracies. I interviewed Nassar in prison. There’s no pride of ownership, as long as it’s out there for the world to consume.”

Sherman just finished a project about Hollywood actress Lana Turner and her ill-fated relationship with Johnny Stompanato for a "Murder in Hollywood" book due this fall. He is also getting access to Ernest Hemingway’s original papers for a long-in-the-works novel about the author.

"It's an interesting premise: a story about Hemingway’s lost suitcase. On a train from Paris to Switzerland in 1922, it contained Hemingway’s early works," Sherman said. "It's probably long gone, but if they (the papers) are out there, it would be a literary holy grail."

Sherman said of all his books, "I call myself an archaeologist of words. I feel like a kid at a candy store when I have original source documents."

Cape Cod Times staff writers Mary Ann Bragg and Gwenn Friss contributed to this story.

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This article originally appeared on The Patriot Ledger: 'Helltown' Amazon series about Cape killer may star Oscar Isaac