By EMILY SHAPIRO, ABC News

(BOULDER, Colo.) — The 21-year-old accused of gunning down 10 people, including a police officer, at a King Soopers grocery store in Boulder, Colorado, on Monday made his first court appearance Thursday.

Ahmad Al Aliwi Alissa, of Arvada, Colorado, was taken into custody about 50 minutes after the shooting was reported. He was charged with 10 counts of first-degree murder and one count of criminal attempt — murder in the first degree.

At Thursday’s court appearance, prosecutors said additional charges are expected in the next few weeks.

Defense attorneys said more time is needed to assess Alissa’s mental health.

Alissa was held without bail and the judge ordered a status conference to take place in about 60 to 90 days.

A possible motive has not been released. According to the arrest warrant affidavit, the suspect bought a Ruger AR-556 pistol on March 16.

The Boulder community gathered in grief at a candlelight vigil Wednesday night, singing “Amazing Grace” through their masks.

The 10 victims range in age from 20 to 65 and include Boulder police officer Eric Talley, who was the first member of law enforcement to arrive at the scene.

The other victims were identified as: 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.

As Talley’s body was escorted from the coroner’s office to the funeral home on Wednesday, fellow officers gathered on roads and overpasses to show their support.

Copyright © 2021, ABC Audio. All rights reserved.