NEW HAVEN, Conn. — A jury has begun hearing evidence as it weighs whether a man convicted of killing a woman and her two daughters during a home invasion should be sentenced to death.

The jury in New Haven is considering punishment for Steven Hayes.

Hayes was convicted earlier this month of killing Jennifer Hawke-Petit and her daughters, 17-year-old Hayley and 11-year-old Michaela, at their Cheshire home in 2007. The jury will decide whether he deserves execution or life in prison.

Testimony began Tuesday with the defense calling Dr. Mark Cunningham, a psychologist.

A former prison official testified Monday that Hayes had threatened to kill a prison guard in March.

Hayes’s attorneys have tried to show their client repeatedly tried to kill himself and was remorseful, while portraying his co-defendant as the mastermind of the attacks.