A 47-year-old man suspected of having walked into a store and killing three people has been detained by police.
Colorado man Scott Ostrem was arrested Thursday morning, approximately 14 hours after the shooting at a Walmart that witnesses said appeared to be random. His arrest followed a brief chase in which Mr Ostrem attempted to flee law enforcement, but was blocked by traffic.
Police had warned the Denver community that Mr Ostrem was "armed and dangerous", and to avoid the suspect if he was seen in public. An anonymous tip later led police to the suspect's home, which is about five miles away from the Walmart.
In interviews, police described a cool-headed shooter who calmly walked into the supermarket before opening fire. After killing two men and a woman, the shooter simply left the building.
"He walked in very nonchalantly with his hands in the pockets, raised a weapon and began shooting. Then he turns around and walks out of the store," Victor Avila, a Thornton police spokesman, said.
Mr Avila indicated that their description of the event was based on several witnesses in the Walmart, who said that the shooting appeared to be random.
Forty-four year old Aaron Stephens said that he was in the self-checkout line in the supermarket when he heard a gun shot, followed soon after by more bursts of gunfire. The scene was pandemonium: Customers were screaming and rushing as quickly as they could to the exits while the shooter casually left.
"I was scared," Mr Stephens told the Denver Post. "I feared for my life."
The shooting was met with hundreds of emergency responders, who circled the Walmart and the shopping centre it is located in.
The three victims have yet to be named by police, though police say that they were the only three victims of the attack. The woman who was shot was rushed to the hospital, but was later pronounced dead by physicians.
Others were treated for anxiety-related conditions following the shooting.
The attack is just the latest gun-related violence in America, where gun violence runs rampant. The US has some of the highest rates of gun violence, including mass shooting events that typically gain broader media attention. The FBI defines a mass shooting as any event in which four or mo
Hundreds of mass shootings have occurred in 2017 alone, according to the Gun Violence Archive, which counts mass shooting events based on the FBI's definition of mass shootings.
The United States has more mass shootings than any other country in the world, a reality punctuated by high--profile incidents like the attack in Las Vegas where 58 people were killed and 500 more were injured after a gunman opened fire on a country music festival. That shooting, the worst in United States history, was just over a month ago. The study indicating that the US has more mass shootings than any other country is more refined than th FBI definition, and does not include gang killings or killings that involve multiple family members.
America also has some of the most lenient gun acquisition laws in the developed world. In many states, individuals are able to buy guns without background checks, and many states also do not ban assault-style rifles, a type of gun designed almost explicitly to kill people, and one with limited practical utility in terms of hunting or recreation.
