Boulder shooting: 10 deaths, including police officer Eric Talley, suspect in custody

"Today we saw the face of evil," the state's governor said.

A total of 10 people were killed, including a police officer, after a gunman opened fire at a King Soopers grocery store in Boulder, Colorado, Monday afternoon, police said.

The officer has been identified by police as Eric Talley, 51. He had been a part of Boulder Police Department since 2010.

A law enforcement source told ABC News officers initially responded to a report of someone being shot in the parking lot of the store, and when they arrived at the scene, a suspect carrying a long gun opened fire on them. Talley was the first officer to arrive at the scene, where he was fatally shot.

A suspect was wounded during the confrontation with police and taken into custody, according to Boulder Police Department Commander Kerry Yamaguchi.

"Our hearts ... go out to the victims of this horrific incident," said Boulder Police Chief Maris Herold at a Monday night news conference, praising Talley for his "heroic action" in responding to the incident after the police department received phone calls of shots fired and of a "possible person with a patrol rifle."

"Officer Talley responded to the scene, was first on the scene, and he was fatally shot," Herold said.

Several other law enforcement agencies soon arrived at the scene, including the state SWAT team.

"Without that quick response, we don't know if there would have been more loss of life," Yamaguchi told reporters at a news conference Monday evening.

The commander and Boulder District Attorney Michael Michael Dougherty said at the news conference that they will be releasing more information on the deceased victims, including the exact number of victims, within the next few hours, as they are still notifying families.

The suspect was not immediately identified by officials, but they said he was sent to an area hospital to be treated for his injuries.

Yamaguchi did not reveal a motive, but said there are no additional suspects at this time.

"Boulder has suffered a terrible and horrific mass shooting today ... this is not the first mass shooting that we have had in the state of Colorado," said Boulder County District Attorney Michael Dougherty Monday night.

"My heart goes out to Eric Talley's family, his loved ones and his colleagues," Dougherty added. "His life was cut far too short. I also want to stress how incredibly sorry I am for all the victims killed today at King Soopers. These were people going about their day, shopping, and their lives were cut abruptly and tragically short by the shooter who is now in custody. I promise the victims and the people of Colorado that we will secure justice."

The police department shared a photo of Talley on Twitter Monday night. "Rest In peace Officer Eric Talley. Your service will never be forgotten #BoulderShooting," they wrote.

Matthew T. Kirsch, acting U.S. attorney of the District of Colorado, also reacted to the deadly shooting.

"This has been a tragic event," he said, adding that he wants to assure both the families of the victims and the community that they will continue to support this investigation as completely as they can.

"My heart goes out to the families of the Coloradans, including a Boulder police officer, whose lives were tragically taken by a senseless act of gun violence," tweeted Colorado Sen. Michael Bennet Monday night. "I am deeply grateful for the swift response from law enforcement and first responders. Enough is enough."

Talley's father, Homer Talley, shared a statement to ABC News following his son's death.

"He took his job as a police officer very seriously. He had seven children. The youngest is 7 years old. He loved his kids and his family more than anything," he said.

Homer Talley said the late officer joined the police force when he was 40 years old and recently started training to be a drone operator so he could get a job to keep himself off of the front lines.

"He didn't want to put his family through something like this," Homer Talley said, "and he believed in Jesus Chris."

The Boulder Police Department took to Twitter at 2:49 p.m. local time to warn residents of an "active shooter" and tell them to stay away from the area.

Then, at 7:10 p.m. ET, they tweeted out an alert asking people about three miles from the shopping center "to shelter in place" while officers responded to a report of an "armed, dangerous individual."

The order was lifted around 8:41 p.m. ET, and Yamaguchi said it was not connected to the store shooting. The investigation is ongoing, and police said anyone with information about the incident should call 303-441-3333.

Eyewitnesses shared videos from the parking lot of the King Soopers grocery store on social media Monday afternoon. The videos show officers ordering a suspect to come out of the store with his hands up and surrender. Videos from inside the store show shoppers and employees trying to flee or hide.

Andy Arellano, a store employee, told ABC affiliate KMGH he was concerned for his co-workers and shoppers as shots rang out.

"We were like sitting ducks, you know, and that's one thing that I'm reliving it and looking at it in my head. And that, that bothers me, I'm still shivering, I'm still shaking," he said.

Eyewitness Andrew Hummel told KMGH he was at a store when he heard the gunshots and ran out of the shopping center with others.

"Everybody kind of sprinted toward the back of the store," Hummel told the station.

Hummel said his roommate, who works at the store where the shooting happened, went to a storage room and hid there with some customers, texting Hummel and others updates.

"Yeah, I think one of the biggest scary text[s] that he sent he just said, 'I love you guys, like thank you for everything, in case, like, things go bad,'" Hummel said. "That was a really hard text ... that's something that I would never want to hear from any of my friends, because I knew the seriousness of what was going on and I was horrified. It was truly horrifying."

Sarah Moonshadow, another eyewitness, told the station she was in the supermarket with her son when she heard four gunshots.

"We were hiding down, kind of in the self-checkout area, and I just knew, like, this is a problem," she said. "And I started counting in between shots and then I just grabbed Nicholas, I said, 'Move now.'"

President Joe Biden has been briefed on the shooting, White House press secretary Jen Psaki said Monday night.

Attorney General Merrick Garland has also been briefed, a Department of Justice official told ABC News.

Colorado Gov. Jared Polis tweeted out a statement Monday afternoon reacting to the shooting.

"Like my fellow Coloradans, I am closely watching unfolding events at King Soopers in Boulder," he wrote. "My prayers are with our fellow Coloradans in this time of sadness and grief as we learn more about the extent of the tragedy."

In another statement later Monday evening, Polis asked for residents to have patience as the investigation continues.

"Right now, the biggest priority is to let local law enforcement and the City of Boulder to do their work to ensure the safety of those involved," he said.

He shared a third statement late Monday night, mourning the lives lost, and showing his support for his community.

"Today, ten lives were tragically lost, including Boulder Police Officer Eric Talley," he said. "And tonight, the families of these victims, our fellow Coloradans, my neighbors, are hearing the devastating news that their loved one who simply woke up and went to work this morning, or who ran out to pick up eggs, won't be coming home."

He said that this year, "we have all been surrounded by loss of life, illness and isolation," and though the ongoing vaccination efforts have brought hope and light, darkness descend again today. "Today we saw the face of evil," he said. "I am grieving with my community and all Coloradans."

Kroger, the parent company of King Soopers, released a statement expressing their condolences and sympathies to their associates and customers and thanking the "first responders who so bravely responded to this tragic situation." They also said they are cooperating with investigators.

United Food and Commercial Workers International Union, the union that represents the store workers, said on Twitter Monday night that they are also monitoring the situation.

Denver-based MLB team the Colorado Rockies shared a statement about the shooting Monday night. "The Colorado Rockies are devastated by today's senseless tragedy in Boulder," they tweeted. "Our heart breaks for the lives needlessly lost and our thoughts are with everyone affected by this shooting. We are grateful for the brave heroes and first responders who acted quickly."

ABC News' Luke Barr and Alexander Malin contributed to this report.