Police officials have identified the shooter at the Mall in Columbia, Md. as 19 year-old Darion Marcus Aguilar, who apparently lived with his mother in the suburb of College Park, where the University of Maryland is located.
Other than that, officials at this point know little about Mr. Aguilar or his motive in the shooting, which left two mall employees dead as well as the shooter, who took his own life.
Was he a student or perhaps an employee at the mall? Did he know the two people he killed, both young employees at a skateboard shop? Did he intend more violence with the shotgun and large amount of ammunition he carried or with the crude explosives made of fireworks and carried in a backpack?
"There are a lot of unanswered questions," Howard County Police Chief William McMahon said at a press briefing.
As the investigation continues, authorities have learned that Aguilar bought the Mossberg 12-gauge shotgun at a local store a month ago. He took a taxi to the mall Saturday, then walked around for about an hour before opening fire. It’s unclear how he was able to conceal the shotgun in a crowd of shoppers.
Although the violence ended quickly, and the rapid response – police arrived two minutes after the first 911 call – reflected a considerable amount of training for just such an event at the mall, it was hours before police could be sure that any other potential threat had been eliminated. When the shooting started, many shoppers and employees had taken refuge in storage areas and dressing rooms, some fashioning barricades.
Ms. Benlolo's grandfather, John Feins, told the Associated Press in a telephone interview from Florida that his granddaughter had a 2-year-old son and that the job at Zumiez was her first since she went back to work after her son's birth.
"She was all excited because she was the manager there," he said. "It's senseless. It's totally, totally senseless.”
Ms. Benlolo had worked at the skateboard store since November 2012, according to her Facebook page, CNN reported. Mr. Johnson had worked at the store for about three months, according to his Facebook page.
Witnesses said they heard 8-10 gunshots fired near the food court on the first floor of the mall. The skateboard shop is on the second level of the mall, just above the food court.
Five people were treated for minor injuries and released from an area hospital, including one who had received a gunshot wound to the foot.
"This was a very scary incident," Howard County Executive Ken Ulman said at a press briefing. "There were a lot of people very close to where this happened."
Columbia, Md. is a planned community between Baltimore and Washington, designed and developed by James Rouse in the 1960s. The mall, which includes more than 200 shops, kiosks, and restaurants, is the commercial center of the town.
Ryan Miller, director of Howard County's Office of Emergency Management, said the mall, which is owned by General Growth Properties and is staffed by private security, allows county police and fire agencies to conduct drills on the property, including active shooter drills, a training tool he said is invaluable on a day like Saturday, the Baltimore Sun reports
"For years we have done exercises and training at this mall," Miller said. "I've been here at 1 a.m. when we've done exercises. ... For [the mall] to open the doors to allow them to orient themselves to the facility is so valuable."
Zumiez, which has more than 400 stores across the United States, said in a statement it was "deeply saddened by the violence" at its store. "Our hearts go out to the victims and their families." The company said it was arranging counseling for its employees in the area.
Police said the mall will remain closed Sunday.
The attack in Columbia follows a shooting at a New Jersey mall in November in which a gunman fired at least six shots without hitting anyone, sparking a mass evacuation of the complex, then killing himself.
"This should not happen at the Columbia Mall," Chief McMahon told reporters. "This shouldn't happen anywhere."
This report includes material from Reuters.