When Richard Hanchett finally learned who his biological mom was, it was already too late.
It was October 2022, and police had made a breakthrough in a decades-old Massachusetts mystery - the mutilated body of a 37-year-old woman found in the dunes of Provincetown in July 1974.
For years, the nameless victim was known as 'The Lady of the Dunes.' Then, DNA tests showed her to be Ruth Marie Terry of Tennessee, and later exposed her then-husband Guy Muldavin as the killer.
Terry had given her son to the Hanchett family in Michigan soon after his birth in 1958. He'd long struggled with her absence, but upon learning she was a homicide victim, his emotions were rocked once again.
'I still have a hard time believing it. It's like a dream,' Hanchett, 66, told DailyMail.com.
'I'm finding out I'm a hillbilly raised as a Yankee, and then to find out she was brutally murdered like that.'
The story of Hanchett, Terry and the 50-year quest to identify her is chronicled in Oxygen's true-crime series Lady of the Dunes: Hunting the Cape Cod Killer, which begins on November 29.
'For the longest time, nobody knew what happened to her and everybody thought the worst,' said Hanchett.
'The documentary gives back the dignity and respect to my mom.'
Terry's body was found in the dunes in Provincetown in July 1974. She was naked, with her hands severed - so she could not be identified by her fingerprints, officials believe.
She was lying on a beach blanket with her nearly severed head and crushed skull resting on her folded jeans.
There was no sign of a struggle, no murder weapon left behind, and her body was decomposing in the heat, which left investigators with few clues.
Her long, reddish-brown hair was held back with a barrette, and she had seven gold crowns on her teeth, worth about $5,000 to $8,000 at the time.
She had been sexually molested with a wooden object, apparently after her death, The Boston Globe reported.
The cause of death was determined to be a blow to the head, and authorities believe she was killed several weeks before her body was found.
For decades, the identity of the 'Provincetown Jane Doe' eluded detectives.
Authorities tried to identify her and her killer by exhuming her remains, performing clay model facial reconstruction, and releasing age-regression drawings of her face.
The macabre mystery roiled Provincetown's idyllic and close-knit community.
Theories about serial killers, a mob hit, and even that the victim was an extra from the movie Jaws, which was filmed nearby, made headlines.
Then in October 2022, the FBI in Boston revealed she'd been identified as Terry through investigative genealogy - the use of DNA analysis in combination with traditional genealogy research and historical records.
The techniques mirrored those used in California to identify a serial killer known as the Golden State Killer.
Previous attempts to trace the DNA had proven unsuccessful.
Investigators then honed in on the life of Terry, who had never been reported missing.
Massachusetts State Police investigators learned she'd left Tennessee to work at a car plant in Michigan.
She gave birth there to her son Richard, but was too poor to support him and he was adopted by the Hanchetts.
She then moved to California, and in 1973 or 1974 married Muldavin, an antiques dealer, in Reno, Nevada.
The couple traveled after their wedding, including stopping in Tennessee to see her family.
Friends at the time noted Muldavin's possessive and controlling behavior over Terry.
Police also learned that Muldavin returned from the trip in the summer of 1974 driving what was believed to be her vehicle.
He told the Terry family that she'd left him after a fight.
Her brother James Terry travelled to California and hired a private detective to track her down.
But his efforts were unsuccessful, and there were reports that she'd joined a cult.
In August 2023, months after they'd identified Terry as the Lady of the Dunes, they determined that Muldavin was responsible for the death.
But it was too late for justice. Muldavin had died in 2002.
He was also a prime suspect in the disappearance of a previous wife and his stepdaughter in the Seattle area in the 1960s, prosecutors said.
'The guy got away with it. He killed multiple people,' said her son, Hanchett.
'You get to a point where you realize you there's nothing you can do.'
The new docuseries features interviews with Hanchett and other relatives, and details about contaminated DNA samples and lost physical evidence from the crime scene.
Provincetown detective Meredith Lobur also lifts the lid on a police chief who tried to put the brakes on her investigation.
Hanchett's book about the saga - Through His Eyes: the Lady of the Dunes, Ruth Marie Terry's Story - also comes out this month.
He talks about his struggle with abandonment and his regret over a time in 1974, when Terry contacted his family in the hope of seeing her then-teenage son.
He declined, because he was recovering from a drug overdose at the time.
He always wondered what had happened to his biological mom, imagining her living a 'rock star' life in California, he says.
In 2018, Hancett used an at-home DNA genealogy service that put him in touch with his maternal family, who told him that his mom went missing in the 1970s.
Four years later, the FBI contacted Hanchett and his Tennessee kin upon identifying the Lady of the Dunes.
As well as learning the shocking truth about what happened to Ruth Terry, they were quizzed about Muldavin, the prime suspect in her death.
'It hurt down in my stomach,' he says. 'And that's gonna bother me to the day I die.'
Hanchett says these past six years have been eye-opening.
Still, the jigsaw of his life is not complete, he adds.
'The only piece that we can't verify is the why. Why did he kill her?' he says.
He wonders whether Terry walked in on Muldavin in a criminal act, or of some other reason he needed to silence her.
'I was hoping the last two years someone would come forward, and tell me why,' he says.
'That was the only thing that I didn't get answered.'