Ahmad Al Aliwi Alissa

On March 22, 2021, a mass shooting occurred at a King Soopers supermarket in Boulder, Colorado, United States.

Ten people were killed, including a local on-duty police officer.

The alleged shooter, 21-year-old Ahmad Al Aliwi Al-Issa, was arrested after being shot in the right leg.

He was temporarily hospitalized before being moved to the county jail.

After undergoing mental evaluations during the legal proceedings, Al-Issa was found mentally incompetent to stand trial in December 2021 and in April 2022.

On August 23, 2023, prosecutors announced that Al-Issa was mentally competent to stand trial; a judge ruled as such on October 6 of that same year.

The shooting began shortly after 2:30p.m. MDT (20:30 UTC) when a gunman entered the parking lot of a King Soopers supermarket and began to fire at people.

He was described by witnesses as wearing an "armored" vest and holding a "rifle", which turned out to be a semi-automatic Ruger AR-556 AR-15 style pistol that was used in the shooting; he also carried a 9mm semi-automatic handgun.

He was first seen by employees and customers who watched him shoot at customers in the parking lot before turning and entering the store.

At the time, there were at least 115 people inside the building and at least 25 others in the parking lot.

The first victim was a repairman who was killed in a van parked next to the gunman's vehicle.

The gunman then walked towards the store; along the way, he killed another person in the parking lot who was trying to flee, shooting him multiple times.

Next, he killed two more people while entering the store through its eastern entrance.

A man waiting in line with his family for his COVID-19 vaccine at the store's pharmacy witnessed the gunman shoot a woman at the front of the line before finding safety in a coat closet with his family.

Some customers and employees reached safety through a back exit for the supermarket.

Some were praised for their actions in helping evacuate and hide individuals away from the gunman.

At 2:33p.m., the Boulder Police Department began receiving calls of a person with a "patrol rifle" in the area and shots being fired.

Witnesses at the scene reported hearing anywhere from ten to thirty shots fired in rapid succession by the gunman.

At 2:34p.m., a Boulder Police dispatcher provided an initial description of the gunman as "a white male, middle-aged, dark hair, beard, black vest, short-sleeved shirt."

The first three responding officers arrived at the scene within two minutes of the first calls and entered the store within 30 seconds of their arrival; at around 2:37p.m., one of the other officers radioed in to say that they were going in.

Running towards gunfire, one of the officers, Eric Talley, was shot and killed by the gunman.

He was the last victim in the shooting, according to Boulder police.

Less than thirty seconds after Talley's death, additional officers entered the store.

By 2:39p.m., responding officers reported being fired upon repeatedly by the gunman.

At around the same time, an armored police vehicle was used to break the store's front windows.

Officers engaged the gunman in a shootout from 3:00p.m. to 3:21p.m. They also used a sound system to order him to surrender.

According to police and witnesses, the gunman was laughing and occasionally mumbling.

A store employee said that while she was hiding, she heard gunshots and screams and then only the store music and phones ringing afterward.

Police did not enter the store again until 3:22p.m., fearing an ambush.

When a team of ten officers from multiple agencies reentered, they encountered the gunman at one of the aisles within twenty seconds of their entry; he fired at them at least twice.

One of the officers returned fire on two different occasions, eventually striking the gunman in the thigh.

He surrendered by saying, "I surrender. I'm naked", and at 3:28p.m., he was taken into custody using Talley's handcuffs.

He had a leg gunshot wound at the time of his arrest, so he was first transported to Boulder Community Health Foothills Hospital.

Police eventually transferred him to the Boulder County Jail, where he was held without bond.

After the gunman was taken into custody, police searched through the store and evacuated people who had remained inside.

A shelter-in-place order was issued in the area at 4:18p.m. and lifted at 6:40p.m. Up to fifteen agencies responded to the shooting, including the Jefferson County SWAT, the Boulder Sheriff's Office, the University of Colorado Police Department, the FBI, the ATF, and local police departments.

A fire department ladder truck was used to get a SWAT team onto the roof.

At least three medical helicopters were summoned to a staging area at nearby Fairview High School.

Ten people were killed:

Officer Talley, who had been working with the Boulder Police Department since 2010, was one of the first police officers to arrive at the scene.