Eight people were killed and five wounded before the shooter ended the horror by taking his own life. He left behind a note that read, in part, "Now I'll be famous."
Robert A. Hawkins, 19, had recently split with his girlfriend and been fired from McDonald's. He had a criminal record and had left or been kicked out of his parents' house.
Police Chief Thomas Warren said the shooting appeared to be random and that the dead included five females and four males, including the gunman. Warren would not release the victims' identities Wednesday night and gave no motive for the attack, but promised more details in a news conference scheduled for Thursday morning.
Hawkins moved from his family's home about a year ago. He moved in with a friend's family, and Debora Maruca-Kovac and her husband welcomed him into their home and tried to help him.
"When he first came in the house, he was introverted, a troubled young man who was like a lost pound puppy that nobody wanted," Maruca-Kovac told The Associated Press.
She told the Omaha World-Herald that the night before the shooting, Hawkins and her sons showed her an SKS semiautomatic Russian military rifle — the same type used in the shooting. She said she thought the gun belonged to a member of Hawkins' family. She said she didn't think much of it — the gun looked too old to work.
Records in Sarpy and Washington counties showed Hawkins had a felony drug conviction and several misdemeanor cases filed against him, including an arrest 11 days before the shooting for having alcohol as a minor. He was due in court in two weeks.
Maruca-Kovac said Hawkins had recently broken up with a girlfriend and was fired from McDonald's. She told the World-Herald that Hawkins said he had been fired after being accused of stealing $17 from his till at the restaurant. McDonald's management declined to comment to the newspaper.
Maruca-Kovac said he phoned her at about 1 p.m. Wednesday, telling her he had left a note. She tried to get him to explain.
"He said, 'It's too late,"' and hung up, she told CNN. She then called Hawkins' mother.
In the note, which was turned over to authorities, Hawkins wrote that he was "sorry for everything" and would not be a burden on his family anymore. More ominously, he wrote, "Now I'll be famous."
Maruca-Kovac went to her job as a nurse at the Nebraska Medical Center, where victims of the shooting soon began to arrive.
The first 911 call came in at 1:42 p.m., and the shooting was already over when police arrived six minutes later, authorities said.
The World-Herald reported that the gunman had a military-style haircut and a black backpack, and wore a camouflage vest.
Hawkins opened fire in a Von Maur store, part of a Midwestern chain.
Mickey Vickory, who worked in the store's third-floor service department, said she heard shots and went with coworkers and customers into a back closet, emerging about a half-hour later when police shouted to come out with their hands up. As police led them to another part of the mall for safety, they saw the victims.
Keith Fidler, another Von Maur employee, said he heard a burst of five to six shots followed by 15 to 20 more rounds. Fidler said he huddled in the corner of the men's clothing department with about a dozen other employees until police yelled to get out of the store.
Witness Shawn Vidlak said the shots sounded like a nail gun. At first he thought it was noise from construction work at the mall.
On Wednesday night, police used a bomb robot to access a Jeep Cherokee left in the mall parking lot that authorities believe belonged to Hawkins. Officers had seen some wires under some clothing, but no bomb was found.
It was the second mass shooting at a mall this year. In February, nine people were shot, five of them fatally, at Trolley Square mall in Salt Lake City. The gunman, 18-year-old Sulejman Talovic, was shot and killed by police.
The shooting spree was Nebraska's deadliest since January 1958, when Charles Starkweather killed 10 people in Nebraska and another in Wyoming.
How is it that everyone missed the warning signs? Should we blame the family or the people he was staying with for not speaking up sooner, for not calling police the same night they saw the gun?