A Colorado man who gunned down 10 people at a Boulder supermarket in 2021 was sentenced to life in prison without the possibility of parole Monday after a jury rejected an insanity defense and convicted him of murder.

Ahmad Alissa, 25, was found guilty on all 55 charges, including 10 counts of first-degree murder, in the assault at King Soopers on March 22, 2021.

Twentieth Judicial District Chief Judge Ingrid Bakke sentenced Alissa to 10 back-to-back sentences of life in prison without the possibility of parole, one for each murder count, as well as other prison terms for the other counts.

Boulder County District Attorney Michael Dougherty said before Bakke imposed the sentence: “This was not about mental illness. This was about brutal, intentional violence, for which he deserves the maximum.”

Alissa, armed with a Ruger AR-556 pistol, opened fire on people at the grocery store before he was shot in the leg by police and arrested.

Jurors deliberated for about six hours after they got the case Friday afternoon.

Alissa remained seated as the verdicts were read and didn’t appear to show any demonstrative reaction. He appeared to speak with his defense team for much of the process.

Alissa’s defense lawyers hadn’t contested that their client as the shooter, but they argued for a verdict of not guilty by diminished capacity because, they said, he couldn’t distinguish between right and wrong when he opened fire. He was later diagnosed with schizophrenia.

Victims, friends and relatives of those killed told the court Monday that their lives had been forever changed. They described being unable to sleep, and a police officer said she was so distraught with post-traumatic stress disorder that she retired from the job she loved for 30 years.

Madeline Talley, daughter of slain Boulder Police Officer Eric Talley, said the last time she saw her dad alive was the night before the shooting.

“I told him I was going to bed, and he gave me a hug. He told me, 'OK, good night,'" she said. “That was the last thing he ever said to me. The next time I saw him, he was in a casket.”

Eric Talley, 51, was the first law enforcement agent to arrive at the King Soopers. He was a father of seven and an 11-year veteran of the Boulder police force.

The other victims 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.

Alissa, who lived in the Denver suburb of Arvada, bought an assault weapon six days before the attack, according to an arrest affidavit.

Outside court, after the verdicts were read, his brother insisted that loved ones didn't reasonably know about his potential for violence.

"We were in the front line. If we knew that he was dangerous, then he was going to be dangerous to us first, before anyone else," older brother Ali Aliwi Alissa told NBC affiliate KUSA of Denver. "His sickness started to become normal to us, that he is antisocial."

Stanisic's sister, Nicolina Stanisic, fondly remembered that her brother, a repairman, was always kind and often bought her ice cream.

"There are no words that describe how much we love and miss him," she told the court during the sentencing phase.

"Our life without Neven is not a complete, whole life. There's someone who is always missing, and that is him in our household," she said. "Before, we could always talk to each other and laugh. And now there's barely anything to talk and laugh about. Most days, it's silent."

Dougherty said after sentencing that the total term handed down was 10 life sentences, with 1,334 years in state prison on top of that.

Alissa “chose to kill as many people as he could at King Soopers” and had been planning it since the beginning of January 2021, Dougherty said.

Erika Mahoney’s father was killed. “I never expected that my dad would have to run for his life in the parking lot of a grocery store,” she said after the sentence.

Erika Mahoney was six months pregnant when her father was killed, and she now has two children.

"If there’s one thing I want for my children and for all of the children in this country, it's that they don't have to grow up with a constant fear of mass shootings," she said. "We have to figure out a way to make them stop."

Madeline Talley, who was 16 when her father was killed, said the shooting robbed her of her dad's presence during life milestones — her driver's license, her first job and her 18th birthday.

"He wasn't there to interrogate my first boyfriend, which he had always told me he would," she said. "Should I get married, he won't be there to walk me down the aisle."

But she also told the court that she forgives Alissa and hopes some day he recognizes the consequence of his actions and reconciles with God.

"My dad did not deserve to die. But if he could say one thing right now, it would be to not let what has happened control my life," she said.