As panicked shoppers fled for cover, workers ushered some into hiding places within stores, or helped them to the exits. The first officers to arrive formed groups and rushed into the chaos, rather than waiting for the more heavily armed SWAT team.
"If we would have run out, we would have ran right into it," said Kaelynn Keelin, who saw a window get shot out and, along with other Made In Oregon co-workers, pulled customers into the store for shelter.
The quick mobilization of mall workers and police reflects the reality that, while mass shootings are rare, they have forced authorities to rehearse for such outbreaks of violence as if they are the norm.
"This could have been much, much worse," Clackamas County Sheriff Craig Roberts said.
Roughly 10,000 people were inside the Clackamas Town Center on Tuesday afternoon, when police say Jacob Tyler Roberts, 22, armed himself with an AR-15 semiautomatic rifle he stole from someone he knew, and went on a rampage that left two people dead.
The sheriff said the rifle jammed during the attack, but the shooter managed to get it working again. He later shot himself. The sheriff and Roberts are not related.
As authorities tried to determine a motive for a shooting they said had no specific targets, details emerged about Roberts from acquaintances and neighbors. They described him as relaxed, friendly and outgoing.
"He was like a rapper. He would rap all the time," said Samantha Bennett, who said she went to middle school with him but wasn't close to him until he moved in with a girlfriend across the hall from her at an apartment complex in summer 2011.
Roberts broke up with the girlfriend about two months later, Bennett said, and later had several other girlfriends. He liked to play video games with Bennett's boyfriend. He never seemed troubled, she said.
His dining room was decorated like a jungle, Bennett said, with vines on the walls and a monkey. He once showed her a black handgun that she believed he purchased legally. He dropped out of sight earlier this year, and his phone was disconnected, she said.
Shooting victims Steven Forsyth, left, and Cindy Yuille
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.
Amid the gunfire, employees helped shoppers get into the backrooms and elsewhere. "Basically, in a situation like this it's either stay right where you're at and lock yourself down, or get to the nearest exit," said Dennis Curtis, the mall's senior general manager.
"We've done drills with the sheriff's office," including one earlier this year, he said.
The first 911 call came at 3:29 p.m. Tuesday and officers arrived a minute later. Instead of waiting for the SWAT teams, police immediately entered the mall.
Police told people in the crowded malls to put their hands in the air, to make sure an armed person was not among them. 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 police found him dead from an apparent self-inflicted gunshot, authorities said.
Families of the dead released brief statements through the sheriff's office.
Relatives of Yuille described her as "everybody's friend" and a caring person. Forsyth was a loving husband, business owner and a youth sports coach, his family said.
As for Shevchenko, it was her second brush with death this year. In August, a man veered his car into the opposite lane and crashed head-on into a van she was in.
Associated Press writers Jonathan J. Cooper, Nigel Duara, Anne M. Peterson, Tim Fought and Sarah Skidmore in Portland, Michelle Price in Phoenix, Pete Yost in Washington, Manuel Valdes in Seattle and researcher Rhonda Shafner contributed to this report.