As authorities tried to determine a motive, details emerged about Roberts from acquaintances and neighbors. They described him as relaxed, friendly and outgoing.
Roberts rented a basement room in a modest, single-story Portland home, said a neighbor, Bobbi Bates. She said she saw him leave at 1:30 p.m. Tuesday, carrying a guitar case.
Police didn't wait
Roberts had several fully loaded magazines when he arrived at the mall, the sheriff said. He parked his 1996 green Volkswagen Jetta in front of the second-floor entrance to Macy's and walked through the store into the mall and began firing randomly in the food court.
He fatally shot Steven Mathew Forsyth, 45, and Cindy Ann Yuille, 54, the sheriff said. Another, Kristina Shevchenko, 15, was wounded and in serious condition on Wednesday, police said.
The first 911 call came at 3:29 p.m. Tuesday and officers arrived a minute later. Police immediately entered the mall.
Police spent hours clearing the 1.4-million-square-foot mall, as some workers and shoppers continued to hide in fear.
Roberts fled along a mall corridor and into a back hallway, down stairs and into a corner, where he apparently shot himself to death, authorities said.