(CBS News) Police say 22-year-old Jake Roberts stole the rifle that he used to kill two people, and himself at an Oregon mall Tuesday.
But they don't yet understand why he did it.
As tragic as the shooting was at the Clackamas Town Center mall, with two dead and another seriously wounded there is also a realization here of how much worse it could have been. The gunman came loaded with ammunition ready for a slaughter, but why he did it remains a mystery even to his friends.
On his Facebook page, Roberts can be seen smiling and happy, and that is the man Sean Stone says he has known for a year-and-a-half. He was shocked when he learned Roberts was the suspected shooter.
Stone said, "I could not believe -- it was like my heart sank into my feet -- I'm getting choked up. Looking for some comfort of what the truth will be."
Stone says he and Roberts sometimes went shooting together. One photo shows Roberts with a handgun. Stone said of the photo, "This is what we did when we were target shooting."
But the targets at the mall were the thousands of people getting ready for the holiday.
According to authorities, Roberts entered the mall through Macy's and headed for the food court. It was there he first opened fire with a semi-automatic AR-15 rifle, killing Cindy Yuille, a shopper, and Steven Forsyth, who had a business at the mall. Then the suspect moved to a service stairwell. At some point, his gun jammed. But he got it working again, and on the lower floor of the mall, turned the gun on himself. Twenty-two minutes after the shooting started, officers found him dead. They also found a third victim -- a bullet had ripped into the chest of 15-year-old Kristina Schevchenko. Trauma surgeons saved her life.
There may well have been more deaths and injuries, but mall workers had trained for an event just like this recently. Thousands of mall shoppers were guided to safe places and the mall was immediately put on lockdown.
For John Blackstone's full report, watch the video in the player above.