Nathan Carman and his mum set out on a trip of a lifetime. Only one of them came home.

After eight days of floating in a life raft at sea, Nathan Carman spotted a freight ship.

The ship's crew rescued him, and he boarded the vessel, soaking wet and 160 kilometres from where his boat, Chicken Pox, sank.

He ate his first hot meal in days, but the circumstances of his rescue immediately raised alarm. A Coast Guard member on the case later noted his suspicion: despite being alone at sea for over a week, Carman was unusually energetic and showed no signs of dehydration or hyperthermia.

Nathan and his mother, Linda Carman, had set off the coast of Long Island, heading for Martha's Vineyard in September 2016, but their boat quickly sank.

From the freighter, Nathan asked the US Coast Guard if they had found his mother. They hadn't, and Linda's body has never been recovered.

She is presumed dead.

This tragic and confounding sequence of events is the subject of the recent Netflix documentary, The Carman Family Deaths.

Watch: The trailer for The Carman Family Deaths. Article continues after video.

Nathan, who was diagnosed with Asperger syndrome (now ASD) as a child, told authorities their boat started to sink after the floor gave way while he was in the wheelhouse.

He claimed he had sent his mother outside to bring in the fishing lines, and after being submerged in the water, he never saw or heard her again. He made it onto the life raft and was blowing a whistle, but notably, he did not place a distress call to authorities.

In the years that followed, Nathan's fragmented story went from one of survival to a much darker, more complicated tale.

Police suspicion grew, as Nathan began specifically describing his grandfather, John Chakalos', wealth.

However, experts argue that authorities misinterpreted Nathan's behaviour. Autism specialist attorney Elizabeth Kelley said in the documentary that Nathan should never have been subjected to an interrogation because neurodivergent people's affect can be misread.

Nathan's father, Clark Carman, also claimed that this misinterpretation turned his son into an unfair suspect.

"Him being a suspect, most of that is due to their inability to discern his demeanour as autistic," he said in the documentary.

Image: Supplied.

The tragic disappearance was only the beginning.

For years, Linda's three sisters — Valerie Santilli, Elaine Chakalos, and Charlene Gallagher — waged a fierce legal battle, known as the "slayer petition," to deny Nathan access to a more than $7 million inheritance.

The aunts alleged in court that Nathan was not only responsible for Linda's death but also the unsolved 2013 murder of his millionaire grandfather, John Chakalos, who was shot dead in his home.

Nathan was an early police suspect in his grandfather's murder, which was carried out by a gun that fired the same calibre ammunition as a rifle Nathan purchased shortly before the shooting.

Nathan claimed he lost the weapon and refused to produce it or take lie detector tests.

Image: Supplied.

Nathan's aunts, as well as the insurance company for the Chicken Pox, alleged Nathan purposely disposed of the weapon and tampered with the boat as part of a plan to inherit millions.

The police never managed to find the murder weapon or evidence strong enough to lay charges for his grandfather's death (which remains unsolved to this day).

After the boat incident, Nathan was sued by his insurance company, National Liability and Fire Insurance Company, who refused to pay out the $85,000 the boat was insured for.

The Boston Herald reported that court documents accused Nathan of tampering with Chicken Pox before the trip, claiming he had enlarged four holes in the hull "near the waterline and attempted on his own to fill them, which was not satisfactory."

A judge ultimately ruled in favour of the insurance companies, denying Nathan's claim and finding that he had made faulty repairs to the boat. As the company's lawyer David Farrell Jr put it: "No wonder the boat sank and Carman's mother died."

Nathan Carman is brought into the USCG Base Boston after being rescued at sea. Image: Getty.

Despite Nathan's father, Clark Carman, publicly standing by his son — stressing that his ASD diagnosis was ignored and that the death was a tragic accident — police investigators didn't agree.

In 2022, six years after the boat sank, Nathan Carman was arrested and criminally indicted for the murder of his mother, Linda Carman, and for fraud related to the inheritance scheme.

Nathan pleaded not guilty to the charges, and his long-awaited trial was set for October 2023.

But the trial never happened.

In June 2023, Nathan Carman was found unresponsive in his jail cell at the Cheshire County Jail in New Hampshire, having taken his own life.

The criminal charges against him were subsequently dismissed.

To this day, the case of Nathan Carman remains one of the most mysterious and tragic family sagas in recent American history.

Feature Image: Netflix.