Here is what we know about the mass shooting in Boulder, Colorado, that left 10 dead

A suspect is in custody, but the motivation behind the massacre still isn’t known, authorities say. Here is what we know so far:

Police said they were called to the King Soopers store over reports of gunfire around 2:40 p.m. MDT Monday.

A man wearing a “tactical” or “armored” vest opened fire, killing people in the parking lot and inside the store, according to a court document released by Boulder County officials the next day.

'Gun, gun, gun! Run, run, run!' Grocery store witnesses describe the deadly rampage in Colorado

An arrest affidavit states police 911 dispatch received multiple calls. One caller told dispatchers the shooter shot out the window of a car and chased a man. Other callers said the shooter was wearing “an armored vest.”

Multiple callers said they were hiding in the store. Employees told dispatchers they “observed the suspect shoot an elderly man in the parking lot. The suspect then walked up to the elderly man, stood over him and shot him multiple additional times,” the police affidavit said.

In scanner traffic, officers radioed that they were in a gunfight. They reported that they were being fired at through at least 3:21 p.m. local time.

Officer Eric Talley, 51.

Witnesses told dispatchers they reported seeing the shooter shoot at police, the affidavit said. Officers had exchanged gunfire with Alissa at the store, but it wasn’t clear who shot him, police Chief Maris Herold said.

Officers wrote that Officer Eric Talley had a gunshot wound to the head and was removed by SWAT officers, the affidavit said.

An officer says they saw the shooter walking backward toward the SWAT team in order to be taken into custody. The shooter “removed all of his clothing and was dressed only in shorts.”

The suspect did not answer officers questions about whether there were other suspects, but he did ask to speak to his mother, the affidavit said.

The suspect was taken into custody at 3:28 p.m. There was no indication of alcohol or drug use, the affidavit said.

At one point, police were seen moving on the roof of the store. The reason for the movements was unclear, but one witness told CNN affiliate KCNC that his relatives in the store were evacuated through the roof.

Who are the victims?

Boulder police Officer Eric Talley, 51, was killed, having been one of the first officers to respond to the scene, Chief Herold said.

Also killed were Denny Stong, 20; Neven Stanisic, 23; Rikki Olds, 25; Tralona Bartkowiak, 49; Suzanne Fountain, 59; Teri Leiker, 51; Kevin Mahoney, 61; Lynn Murray, 62; and Jody Waters, 65, police said Tuesday.

A young grocery store manager and a heroic officer were among the 10 Boulder shooting victims

Talley, a father of seven children ages 5-18, once had a different profession and “didn’t have to go into policing, but he felt a higher calling,” Herold said.

“He cared about this community … and he was willing to die to protect others,” she said.

Olds, 25, of Lafayette, was a front-end manager at the store, her uncle, Bob Olds, told CNN.

She was a “strong, independent young woman” who was raised by her grandparents, Bob Olds said. “She was so energetic and charismatic and she was a shining light in this dark world,” he told CNN.

A Colorado State Police officer salutes as a procession carrying the body of a fellow officer leaves King Sooper's grocery store.

Olds and another victim were graduates of local high schools, according to a statement from Boulder Valley School District Superintendent Rob Anderson.

Olds was a 2013 graduate of Centaurus High School and Stong was a 2019 graduate of Fairview High School.

Who is the suspect?

Ahmad Al Aliwi Alissa, 21, of the Denver suburb of Arvada, was taken into custody at the shooting site, accused of killing the 10, police said.

Alissa was shot at some point in the leg. Officers had exchanged gunfire with him at the store, but it wasn’t clear who shot him, Herold said.

Here's what we know about the Boulder, Colorado, mass shooting suspect

He was treated for his injury at a hospital, but by Tuesday he had been booked into a county jail on 10 counts of murder in the first degree, police said.

Investigators don’t have information about a motive. Still, they believe he was the only perpetrator, authorities said at a news conference Tuesday.

The suspect has “lived most of his life in the United States,” Boulder County District Attorney Michael Dougherty said, without elaborating.

“In terms of statements that he (Alissa) may have made to investigators … we’re collecting those statements now, and we’ll be providing those in the weeks ahead,” Dougherty said.

This image shows police escorting Ahmad Al Aliwi Alissa from the supermarket Monday, according to this brother.

An AR-15-style pistol that had been modified with an arm brace was used in the shooting, a senior law enforcement source told CNN on condition of anonymity. A search of the suspect’s home turned up other weapons, the source said.

Images from the scene on Monday — from a livestreamer and from CNN affiliate KMGH — showed police escorting from the building a shirtless man with blood on his leg, with his hands apparently cuffed.

That man was the arrested suspect, Ahmad Al Aliwi Alissa, his brother, Ali Aliwi Alissa, told CNN.

Sarah Moonshadow is comforted by David and Maggie Talley after Moonshadow was inside King Soopers grocery store.

Where does the investigation go next?

Police will be on the scene day and night to learn more about the violence that took place at the store, officials said.

“We will work around the clock to get this accomplished,” Herold said.

The killings come less than a week after three spa shootings in Atlanta, in which eight people were killed.
In the last week, the United States has had at least seven shootings in which at least four people were injured or killed.

CNN’s Steve Almasy, Paul P. Murphy, Whitney Wild, Blake Ellis, Melissa Gray, Keith Allen, Jennifer Feldman, Konstantin Toropin and Joe Sutton contributed to this report.