PORTLAND, Ore. — Before police say Jacob Tyler Roberts went to a mall wearing a hockey-style mask, shooting numerous rounds that killed two people and injured a teenage girl, he visited the brother of his roommate, hugged him, and told him he was going ‘‘somewhere south, somewhere warm.’’

The roommate, 26-year-old Jaime Eheler, also said that when Roberts left the house they shared, ‘‘he had a weird look on his face.’’