ROCKPORT — The father of a Maine man accused of killing three family members and a caregiver says he doesn’t understand how his son could have committed such violence.

Alexander Krause told The Boston Globe that his 22-year-old son was a “stellar student” who recently graduated from Oberlin College. Krause said the killings underscore the need to “pay more attention to mental health,” but declined to elaborate.

Krause told the newspaper that there are “so many unanswered questions.”