CLACKAMAS, Ore. - After months of interviewing 227 people and fielding 311 tips, investigators said Wednesday they still have no idea why Jacob Tyler Roberts opened fire in Clackamas Town Center, killing two people and seriously injuring a third.
Clackamas County sheriff's investigators on Wednesday released 926 pages of police reports looking at why Roberts, 22, opened fired in the mall on Dec. 11, during the height of the busy Christmas shopping season.
They say Roberts had no criminal history, no known ties to the mall, no history of violence and no history of diagnosed mental illness.
Inexplicably on Dec. 8 -- a week after breaking up with his girlfriend and telling friends he was moving to Hawaii - Roberts purchased two 30-round AR-15 magazines from a local gun shop and two 20-count boxes of .223 ammunition, according to investigators. He also bought ear plugs and paper targets.
The next day, he bought several more magazines and ammunition.
Here's a timeline that detectives compiled of Roberts' actions the day of the shooting:
- That morning, Roberts gave no indication to friends of his shooting plans. He told one friend that he decided not to go to Hawaii, but didn't want others to know and told the friend he still planned to leave town.
Around the time Roberts confided in his friend, Sean Cates, Cates showed Roberts his AR-15 rifle. The two also drank, played pool together and smoked marijuana at Cates' house at about 1:30 a.m.
- Later that morning, at 5 a.m., Roberts, who was sleeping on Cates' couch, stole his friend's AR-15 rifle. Around noon, roommates told investigators that Roberts stopped by the home, talked briefly with them and left with a pair of boots and a small plastic bag of clothes, according to police reports.
- Just before heading to Clackamas Town Center, Roberts stopped at another friend's house and the two discussed Roberts' purported plans to move to Hawaii and smoked marijuana together.
- At 3:15 p.m., Roberts left his friend's house.
- Fifteen minutes later, Roberts, carrying a rifle, was seen entering Macy's parking lot. He left his windshield wipers running and his ID in his car.
- At 3:29 p.m., 9-1-1 dispatchers began receiving calls, the first one coming from the Macy's store. Roberts was seen wearing a white hockey mask, black coat and pants and carrying a rifle into the Macy's home store.
- Roberts unleashed a barrage of gunfire within the next two minutes. Cindy Yuille, Kristina Shevchenko and then Steve Forsyth were shot in the upper-level food court area, just outside the interior entrance of Macy's. Yuille and Forsyth both died; Shevchenko survived. Shevchenko was shot as she ran away from Roberts.
- Roberts fired 13 more rounds that didn't hit anyone. Witnesses described the scene like a war zone. Some witnesses said he pointed a rifle at them, but did not shoot and continued running.
One woman said "the shooter passed close to her and looked directly at her. She said she didn't understand why he didn't shoot but he continued eastbound," a deputy wrote in a police report.
People at the mall were running frantically to seek hiding spots. "While in the cinema, I noted beverage and food items spilled on the floor as if people had left where they stood and fled," another deputy wrote in a police report.
- At 3:51 p.m., he was found dead of a self-inflicted gunshot wound to the head in the hallway near JC Penney in the lower level of the mall.
Roberts was found armed with a Stag Arms AR-15, a semiautomatic rifle. He had 145 unfired ammunition rounds in five magazines, according to police reports.
A toxicology report later showed marijuana in his system as well as a low level of cocaine indicating he had used the drug 36 to 48 hours before the shooting.
The report details how in the first minutes of the shooting, a bystander named Nicolas Meli waved deputies over and said a man was firing into the crowd when either he ran out of ammo or his rifle jammed.
Meli was armed with a handgun himself, for which he had a permit to conceal.
Meli told police after the shooting that he had a clear shot at Roberts, but was afraid he would miss and shoot someone else.
"I didn't want to draw attention to myself because if I was to miss ... I didn't want stray (bullets) to go into where they were," Meli told police in an interview later.
Investigators said in a news release they are confounded by the shooting rampage.
"To date, a motive for this crime has not been determined, despite exhaustive and far-reaching efforts by investigators that included interviews with hundreds of witnesses as well as family members, co-workers and friends of Jacob Roberts," according to the news release from the Clackamas County Sheriff's Office.
Roommate finds meth, ammo in Roberts' room
Roberts' roommate, Chris Dahrens, told detectives that after seeing news of the shooting, he "immediately became suspicious of his roommate," according to police reports.
While he didn't believe Roberts showed signs of violence, he thought his roommate fit the physical description.
Dahrens said he decided to search Roberts' room. There, he found packages of 30-round AR magazines, receipts and empty ammunition boxes.
Later that day, Dahrens checked the room again and found a zip lock bag of a white substance that looked and smelled like methamphetamine. He said he wasn't aware Roberts did meth.
Deputies later executed a search warrant and found those items described by Dahrens. They also found handwritten notes showing Roberts' flight plans to Hawaii.
The Associated Press contributed to this report