[UPDATE] 11:38 AM Sept. 29, 2016
Officials say Nathan Carman was a suspect in an unsolved 2013 killing of his rich grandfather, the Washington Post reports.
Coast Guard officials interviewed Carman, and police searched his home in Vermont as part of an investigation into the fishing trip that left his mother missing and presumed dead.
He has not been charged with any crime in either case.
A 22-year-old man was found off the coast of Massachusetts on Sunday afternoon after eight days lost at sea and two days after the Coast Guard had called off its search.
Nathan Carman, 22, and his mother, 54-year-old Linda Carman, both of Middletown, Connecticut, set out on a fishing trip on Sept. 17 from Ram's Point Marina in Point Judith, Rhode Island.
They were first reported missing Sept. 18 when they didn't return home from the trip.
Nathan Carman was found floating on an inflatable raft about 100 nautical miles south of Martha's Vineyard, Coast Guard Petty Officer 3rd Class Nicole Groll told the Washington Post.
Groll added that his life raft was stocked with food and water.
Nathan's mother was not with him when he was rescued, so the Coast Guard is still investigating what happened to her.
Linda Carman's close friend, Sharon Hartstein told the Hartford Courant that Linda and Nathan go out on a fishing trip at least once a month.
She said they usually leave the marina late at night or early in the morning to fish.
When the mother and son didn't return on Sept. 18, the Coast Guard was alerted.
The family's boat has not been located, according to ABC News.
This isn't the first time Nathan Carman has made headlines, according to the Connecticut Post. In 2011, when he was 17, Nathan Carman wandered away from his home in Connecticut.
At the time, authorities warned anyone who might see him not to touch him because he has Asperger's Syndrome, a form of autism.
He was found in Virginia four days later.
For more news, check out today's 60 Second Circa.