The masked gunman who terrorized holiday shoppers at an Oregon mall, killing two people and himself, was a 22-year-old Portland man with an assault rifle that police say had been stolen a day earlier.
Clackamas County Sheriff Craig Roberts said Jacob Tyler Roberts did not know his victims and did not appear to have specific targets when he fired as many as 60 shots inside a mall crowded with 10,000 people Tuesday afternoon.
A 15-year-old girl, Kristina Shevchenko, was in serious condition following surgery after being shot in the chest while cutting through the mall after classes at a nearby high school. She managed to get outside the mall on her own, despite her wound.
"She is doing as well as we can expect,'' said Laszlo Kiraly, the trauma surgeon who treated her at Oregon Health and Science University. He said she was in stable condition with life-threatening injuries, and that when she arrived at the hospital she had a collapsed lung and damage to her liver.
"What she had to do to get out of that situation -- (it) is clear to me that she is a very brave young woman." Kiraly said. "We are very impressed with her courage."
Kristina's brother, Yevgeniy Shevchenko, posted on Facebook: "None of the vital organs were hit and she is doing well after the first operation. She will have a couple more operations in the following week."
Roberts said the carnage "could have been much, much worse."
He said the shooter's gun, an AR-15 semiautomatic assault rifle, jammed after he began firing near a Macy's store on the upper level of the mall. He was able to get it working again, then fled along a corridor, down stairs and into a corner of the mall where he shot himself, the sheriff said.
"Every indication we have is that he acted solely on his own in carrying out this heinous, horrible crime," he said.
He said the gunman wore a mask and a combat-style -- but not bulletproof -- vest and parked his 1996 Volkswagen Jetta in front of the second-floor entrance to Macy's, where he entered the mall.
The sheriff said the man had stolen the gun from someone he knew the day before his bloody rampage.
When the shooting started, many shoppers immediately took cover or hid in stores inside the mall.
"Ten thousand people kept a level head, got themselves out, got others out," Roberts said. "There are a lot of heroes."
Brance Wilson, 68, was greeting children as the mall's Santa Claus when the shooting began. About to invite a child to hop onto his lap, Wilson said he instead dove for the floor, kept his head down and crept toward better cover.
Killed were Cindy Ann Yuille, 54, of Portland, and Steven Forsyth, 45, of West Linn.
Yuille, a hospice nurse, "was everybody's friend," her family said in a statement. "She was a wonderful person who was very caring and put others first."
Forsyth, a married father of two, ran a custom wood design business and owned a marketing company, state records show.
"Steve was one of the most passionate people, with a true entrepreneurial spirit,'' his family said in a statement provided by the Clackamas Sheriff's Office.
The shooting is the latest in a series of mass murders in public places by young men armed with powerful semiautomatic firearms.
James Alan Fox, professor of criminology at Northeastern University, said there has not been a rise in mass shootings. He said shootings in public places get more attention because the randomness illustrates the vulnerability in everyday places.
"Public shootings tend to attract more attention, and they do so because they could have happened any time, everywhere and even to me," Fox said. "In massacres in families, we can say, 'That wouldn't be my family.' In work place murders, we can say, 'People at my job are content.' The randomness of public incidents scares us all."
Darrel Stephens, executive director of the Major Cities Police Chiefs Association, said rapid response is "critical to minimizing death and injury'' in public shootings.
"These incidents have been happening with such frequency that each case seems to influence how police train to respond,'' said Stephens, who directed the Charlotte-Mecklenburg, N.C., Police Department.
The 1999 mass shooting at Columbine High School near Denver, which left 12 students, one teacher and the two shooters dead, offered perhaps the most dramatic example of the need for a coordinated police response, Stephens said. In that Columbine case, a gubernatorial commission faulted police for failing to confront the shooters immediately.
"What we learned from Columbine was critical,'' Stephens said. "Waiting only provides more opportunities for attackers to do more damage.''
Contributing: Donna Leinwand Leger, Kevin Johnson, Natalie DiBlasio, John Bacon, Yamiche Alcindor; the Associated Press