BOSTON (AP) — Court records show that a Vermont man who spent a week on a life raft in the Atlantic Ocean before he was rescued recently was a suspect in the unsolved 2013 killing of his grandfather in Connecticut.

Nathan Carman, of Vernon, Vermont, was rescued Sunday. His mother, Linda Carman, of Middletown, Connecticut, is still missing and presumed dead. Nathan Carmen told the Coast Guard he and his mother were on his fishing boat when it sank.

Documents obtained by The Hartford Courant show that Nathan Carman was investigated in the fatal shooting of 87-year-old John Chakalos.

According to a search warrant, Carman was the last person known to see his grandfather alive on Dec. 20, 2013, because he had dinner with him at his home in Windsor, Connecticut. Chakalos was found dead the next morning.

The Courant reports that Windsor police submitted an arrest warrant for Carman to a prosecutor, but it was returned unsigned with a request for more information. Carman was never charged.

Carman's lawyer, Hubert Santos, declined to comment.