Ahmad Alissa, Boulder Shooting Suspect, to Appear in Court

The man accused of murdering 10 people in a mass shooting in Boulder, Colorado, is due to make his first court appearance.

Ahmad Al Aliwi Alissa, 21, is set to appear before District Judge Thomas Francis Mulvahill on Thursday, unless he waives his right to do so.

The suspect will not be asked to enter a plea and instead will be advised of the charges against him, and his rights as a defendant.

Alissa has been charged with 10 counts of murder in the first degree in connection to the shooting at a King Soopers at around 2:30 p.m. on Monday. Detectives have yet to reveal a possible motive for the mass shooting.

The suspect bought a Ruger AR-556 pistol on March 16, six days before the attack, an arrest affidavit revealed. It is not known where the 21-year-old purchased the firearm.

Boulder Police officer Eric Talley, 51, was the first victim to be identified. Police Chief Maris Herold praised Talley's actions as "heroic" and confirmed he was the first on the scene when he was fatally shot.

The other nine victims have been named 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.

Chief Herold said in a statement: "Our hearts go out to all of the victims killed during this senseless act of violence. We are committed to a thorough investigation and will bring justice to each of these families. The Boulder community is strong and compassionate, and I know we will come together to take care of each other during this time."

On Wednesday, hundreds of police officers and residents lined streets to pay respects to Talley as a hearse carrying his body was driven from the coroner's office in Boulder to a funeral home in Aurora.

"Thank you to everyone who lined the roadways, overpasses and more this afternoon to show your support," the police department tweeted. "Words can't express just how much this meant to us #BoulderStrong."

A large vigil for the victims was also held on Wednesday night in Boulder which included a moment of silence, violins, and one woman singing "Ave Maria," reported the Associated Press.

"Whatever you're feeling, whatever you're thinking, no matter how uncomfortable, it's completely natural," Michele Weiner-Davis, a Boulder family therapist, told the crowd.

"Be patient with yourself. Additionally, be just as compassionate with the people in your lives who might also be struggling."