Soon after a shooting incident at a store in Boulder, Colorado, police could be seen leading away a suspect -- a middle aged white man, shirtless and wearing shorts. Ten people, including a police officer, were killed in the deadly incident at King Soopers super store. In the videos shared online, people were seen lying injured in the parking lot of the store.

"The shooter is being held in custody and was injured," said Michael Dougherty, district attorney for Boulder County. Though police are yet to give out any details about the shooter, several eyewitnesses have give accounts of what they saw. Denverpost.com reported accounts of two roommates who were buying pizza at the self-checkout. After hearing the initial noise, they saw a gunman, clad in black, enter with a rifle of some kind. He said nothing before raising the gun, they said, the website reported.

“He just came in and started shooting,” said one of the men, who spoke to The Denver Post on condition of anonymity to avoid national publicity. His friend added that the gunman “let off a couple of shots, then was silent, and then he let off a couple more. He wasn’t spraying.”

Another eyewitness reported seeing officers walking a handcuffed man out of the store. The man seemed to be wearing only underwear and was bearded and heavyset. "The man’s leg was bloody," he added.

A grandfather narrated how his teenaged granddaughters survived the attack as their father led then to a coat closet, where they hid for close to an hour before help arrived.

Also read: 2 sisters hide in coat closet for an hour, survive Boulder shooting

Among those dead was "heroic" police officer Eric Talley, 51, who was the first to respond to the scene at a King Soopers supermarket, said police chief Maris Herold.

This is the fourth fatal shooting incident in the US this year. On March 20, five people were killed in shooting incidents in Houston and one in Dallas. On March 16, a series of mass shootings occurred at massage parlors in Atlanta and its suburb Acworth. Eight people were killed in the incidents and one person was wounded. In another incident on March 14, four people were shot in Tampa, Florida outside a banquet hall.