Thornton, Colo: The police in Colorado on Thursday captured a man who they had said calmly walked into a suburban Denver Walmart and fatally shot three people before driving away.
He walked in the front door of the Thornton Walmart and opened fire on shoppers with a handgun.
A man suspected of walking into a Walmart store in Colorado and "nonchalantly" shooting to death two men and a woman has been arrested, police said Thursday.
The suspect was identified as Scott Ostrem, 47.
After the shooting, it took five hours for law enforcement to notify the public that a suspect in the triple homicide was still on the loose and to distribute his photo.
What they do know is that it is not believed to have been an act of terrorism. Authorities used security video to help identify him.
Court records show a resisting arrest charge against Ostrem was dismissed in 1999.
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This meant they couldn't send a Walmart employee into the store to immediately review surveillance footage, since police still had to secure the scene and make sure it was safe.
Thornton Police Department spokesman Victor Aliva told reporters, citing witness accounts, that the attack appeared "random".
Authorities did not immediately release any other information about the victims.
According to Aaron Stephens, a witness who spoke to the Denver Post, he was in the self-checkout line when he heard a single shot fired, followed by more bursts of gunfire.
An hour later, the Thornton Police Department tweeted, "At this time this is not an active shooter".
"The employees started screaming and the customers started screaming" as people began to flee the store, he recounted.
Authorities are reviewing security video to identify the suspect, who fled in a vehicle before officers arrived.