Police in Colorado have taken Scott Ostrem, 47, into custody for fatally shooting three people in a suburban Denver Wal-Mart before driving away.
Ostrem "nonchalantly" entered the store in Thornton, about 10 miles (16 km) northeast of downtown Denver, and opened fire on shoppers and employees a little after 6 p.m. time, Thornton Police Department spokesman Victor Avila told reporters, citing witness accounts.
"What we have determined is that it is random as of right now," Avila said. "As witnesses stated, the person came in and just shot towards a group."
Two men were killed in the shooting and a woman who was shot was taken to a hospital where she died, according to the police department.
Avila told Reuters that Ostrem was a "local" but said he could not give more details while the investigation is under way.
Police had initially said "multiple parties" were injured in the shooting and told the public to avoid the area. The Wal-Mart was quickly surrounded by police and fire crews. About an hour after the initial alert, authorities said the threat of gunfire had ended.
Avila said there was no indication the shooting was an act of terrorism as no one has claimed responsibility.
"We can't rule anything out," he said.
Wal-Mart customer Aaron Stephens, 44, of Thornton told Reuters he was buying groceries at a self-checkout stand when he heard gunshots and ricocheting bullets.
"The employees started screaming and the customers started screaming" as people began to flee the store, he said. "I ran out, too, because I didn't want to get shot."
Stephens said he did not see where the shooting had come from and did not see anyone struck by bullets.
NBC television affiliate 9NEWS reported a woman whose son was in the Wal-Mart said he heard about 30 gunshots.
