CONCORD, N.H. — A man suspected in the 2013 slaying of his millionaire grandfather plans to represent himself in his family's attempt to bar him from receiving an inheritance.

Nathan Carman was a suspect in the shooting death of his maternal grandfather, 87-year-old real estate developer John Chakalos, in Connecticut. No one has been arrested.

Last year, a boat carrying Carman and his mother, Linda, on a fishing trip near Rhode Island sank. She's presumed dead.

Her three sisters have sued in New Hampshire, accusing him of killing his grandfather and possibly his mother. They asked a judge to block Carman from collecting money from the estate.

Carman lives in Vernon, Vermont.

He has denied any involvement in Chakalos' death and says he didn't sabotage the boat.