SAN DIEGO — San Diego County investigators trying to determine a motive behind a New Year's Day murder-suicide involving two Navy pilots and two other people are looking at whether jealousy may have played a role.

Sheriff's Capt. Duncan Fraser said Thursday investigators are looking at all aspects, including whether there was a relationship between one of the pilot's sisters who was also killed and the Navy pilot who committed suicide.

John Robert Reeves shot himself in the head, and the three others with him were murdered at the condominium in Coronado.

They included Navy pilot David Reis, his sister Karen and 31-year-old Matthew Saturley of suburban Chula Vista.