BOSTON (AP) - A man who was rescued from a life raft after seven days on the Atlantic says suspicions about his account of the sinking of his boat are compounding his grief over the apparent drowning of his mother.

Twenty-two-year-old Nathan Carman was picked up by a passing freighter Sunday about 100 miles off the coast of Massachusetts after what he said was a week adrift that began when his aluminum fishing boat sank during a mother-and-son fishing trip.

Coast Guard officials interviewed Carman and police have searched his Vermont home as part of their investigation.

Carman says he loved his mother and is still trying to come to terms with the tragedy.

Authorities say Carman was a suspect in the unsolved 2013 slaying of his 87-year-old grandfather. He was never charged.