TRURO - He wrote a sprawling biography of Norman Mailer, but years later the two became such bitter enemies that Mailer described him as a "poison-drip."
He infuriated many in Provincetown with a gossipy book lamenting that the resort town has become a place where moneyed gays and lesbians talk mostly about real estate and remodeling.
And he nearly sank Arnold Schwarzenegger's 2003 gubernatorial bid in California with a long-forgotten 1977 article in a skin magazine about the young bodybuilder's sexual escapades.
Peter Manso, viewed by some as a self-promoting gadfly and others as a fearless truth-seeker, seems genetically predisposed to controversy. And now the 67-year-old Truro author, a bantam-sized and gravel-voiced Zelig of causes célèbres, is in the thick of another in his own backyard.
He has spent nearly three years working on a book for Simon & Schuster about the murder of Christa Worthington, the white fashion writer who was raped and stabbed to death in her house in a notorious 2002 slaying. Although he hasn't finished the reporting, Manso has unequivocally thrown his lot in with the defendant, Christopher M. McCowen, the black trash collector convicted of the crime in November 2006 in Barnstable Superior Court.
Indeed, Manso has become a virtual member of the legal team seeking a new trial, one who just happens to sit in the spectators' gallery jotting in orange French-made notebooks at court hearings instead of at the defense table.
"I have no problem with saying I'm on the side of the defense [and that] I've worked on behalf of the defense when it dovetails with my book's research," Manso said recently at his house. "I happen to believe that the verdict in the Christopher McCowen case is vastly off the mark and that the racism I have found to be behind that verdict is something I feel I have to expose here on my Cape Cod" - he pauses, then emphasizes - "my Cape Cod."
McCowen, who is serving a life sentence, is seeking to have his conviction thrown out based on allegations that jurors were racially biased. And Manso has often acted like an unpaid private investigator and legal associate for McCowen's defense lawyer, Robert A. George, drawing criticism from people associated with the Worthington case and prompting media specialists to issue notes of caution.
In recent weeks, Manso has dug up what he describes as exculpatory evidence and boasted of ghost-writing the resulting defense motion. He led George to a woman who challenged the truthfulness of a juror who testified at a hearing about possible racial bias. He even asked George to deputize him before the murder trial to let him cross-examine a key witness in court - a move that, it turns out, is illegal in Massachusetts.
Manso recently learned firsthand how it feels to be investigated by police on the Cape. Truro police responded to a burglar alarm at his unoccupied house in December and seized three firearms - including an assault rifle - allegedly without trigger locks and without his having a valid firearms license. Chief John Thomas said charges will be filed soon and that Manso will be arraigned in June.
Manso declined to discuss the episode on the advice of counsel. But given his strident criticism of the Worthington investigation - he told the Globe that police misconduct is so egregious that it makes him think "the Cape is a suburb of redneck Mississippi" - some relish his travails.
"The justice in all this is simply divine," wrote Peter Kenney, a Yarmouth blogger for CapeCodToday.com. "Now Manso will experience firsthand the effectiveness of all those same law enforcement officers he so arrogantly dismissed as fools and incompetents."
Manso's role in McCowen's bid for a new trial has drawn criticism from people with ties to Worthington, including Tony Jackett, the shellfish constable who fathered her daughter, Ava.
Jackett, who was widely considered a suspect in the investigation and figured prominently in Manso's controversial 2002 book "Ptown: Art, Sex, and Money on the Outer Cape," said the writer is a shrewd self-promoter who wants a new trial for McCowen largely as fodder for his upcoming book. Manso is bitter that another Truro writer, Maria Flook, beat him with a 2003 book about the crime, "and he's been chomping at the bit ever since," Jackett said.
"His whole career legacy is hinged on this story," said Jackett, who calls Manso "very bright" but also "a bully, intimidating, and shameless."
Still, Jackett said he is among many on the Cape who believe that another person may have been involved with McCowen in the slaying and that the defendant may deserve a new trial.
McCowen told police after his arrest that a friend, Jeremy Frazier, was with him when Worthington died and that it was Frazier who killed her. Frazier denied having anything to do with the crime at the trial.
Relatives of Worthington had no comment about Manso. Cape and Islands District Attorney Michael O'Keefe also declined to comment.
Manso concedes he enjoys stirring things up but says he does so to expose the truth. "I like to counterpunch, I like to butt heads," said the white-haired writer, who grew up in Manhattan and began spending time in Provincetown in the 1950s with his mother and father, an abstract-expressionist artist.
Among those who have tangled with him are Mailer, a onetime friend and the subject of Manso's 1985 book: "Mailer: His Life and Times." In 2002, Mailer, still apparently upset by how Manso portrayed him, wrote The Provincetown Banner to call him a "poison-drip" and say Manso "is looking for gold in the desert of his arid inner life, where lies and distortion are the only cactus juice to keep him going."
Manso says their falling-out had nothing to do with the biography but stemmed from what he called a foolish decision to buy and share a house in Provincetown with Mailer, who "could be a very, very vicious man."
These days, Manso has become a de facto associate of George, a veteran defense lawyer who says police targeted McCowen largely because of his race. Manso has dug up evidence that some of the state's trial witnesses, including Frazier, had extensive criminal records that prosecutors allegedly withheld from jurors. That resulted in a pending motion that Manso boasted of writing, although he later back-pedaled a bit on the assertion.
Manso also led George to Delainda Julia Miranda of Mashpee, who testified Feb. 1 that her grand-nephew, a juror, lied when he testified last month in Barnstable that he did not hold racist views.
Judge Gary A. Nickerson interviewed a dozen jurors after three told George shortly after the verdict that other jurors made racist remarks. Nickerson is expected to rule on the motion for a new trial within a few months.
"If Peter was allowed to write every piece of paper submitted in the case and argue it on his feet before the court, he would do so," George said.
He called Manso "an invaluable, indispensable, completely dedicated friend of the defense" but said he has paid him nothing and denied that Manso wrote any motions.
Alex S. Jones, director of Harvard University's Shorenstein Center on the Press, Politics, and Public Policy, said Manso is acting within the tradition of advocacy journalism - a bona fide form of journalism, he added, but unabashedly subjective.
"There is nothing objective in his approach," he said. "The question would then be, what would he do if he found evidence that was not helpful to his client? I wonder if he'd make it public."
Manso said he would, and has repeatedly tried to interview prosecutors and police, to no avail.
"The simple dynamic in this whole thing is I'm trying to find the truth," he said.
Jonathan Saltzman can be reached at jsaltzman@globe.com.
