One of the three co-defendants in the rock-throwing death of 20-year-old Alexa Bartell was sentenced to 45 years in prison in a Jefferson County court room Thursday.

First Judicial District Judge Christopher Zenisek sentenced 20-year-old Nicholas “Mitch” Karol-Chik to 45 years in prison and eight years of probation on one charge of second-degree murder with a crime of violence enhancer and attempted first-degree murder in connection to the death of Bartell on April 19, 2023.

He was officially sentenced to 45 years on the second-degree murder charge and 24 years on the attempted first-degree murder charge, both set to run concurrently.

Karol-Chik’s father, Michael Karol-Chik, sat with his head in his hands, shedding tears throughout the sentencing hearing as several members of Bartell’s family shined a light on the life of the young girl killed by the trio.

“I am serving a life sentence of pain,” Kelly Bartell, Alexa Bartell’s mother, said at the stand before showing a four-minute video to the judge with snapshots of Alexa Bartell’s life, filled with singing, dancing and youthful smiles.

Kelly Bartell, along with the rest of the family that spoke, called Alexa Bartell beautiful, joyful and impactful on everyone she met.

The mother added that Alexa’s dog still sleeps in her bed every evening, even two years after her death.

“The last two years for us have been pure hell,” Erin Miller, Bartell’s cousin, said. “We have lived in a constant state of grief. None of us know how to accept or process her absence.”

Miller added: “My family isn’t the same anymore. When we’re together, there is such a heaviness along with a massive void. We are the ones left with silence and an empty chair at every gathering.”

Behind Miller sat a full section comprised of Bartell’s loved ones. The same group sat through the entirety of the two-week trial where 20-year-old Joseph Koening — the one who allegedly threw the rock while driving Karol-Chik’s truck — was found guilty of first-degree murder and 18 other charges regarding rocks thrown at nine other victims’ vehicles while driving.

The incident happened near the 10600 block of Indiana Street near Rocky Flats Wildlife Refuge around 11 p.m. when Bartell was driving a yellow Chevrolet Spark to her gilfriend’s house.

Karol-Chik then handed Koenig a 9-pound landscaping rock. Koenig sped up to at least 80 mph and threw the rock from the driver’s side window, striking and killing Bartell.

Jenna Griggs, Bartell’s girlfriend, was the first to arrive on the scene after seeing that Bartell’s car had stopped moving near the area.

“I hate driving down two-lane roads. I hate being in the dark. I hate driving at all because I now have nightmares of things I had to see that night,” Griggs said Thursday.

Griggs was not the only person left with nightmares after the incident.

Karol-Chik and Koenig threw rocks at at least 10 vehicles, including Bartell’s, during three separate nights between February and April 19. All nine of the other victims testified during Koenig’s trial.

Nathan Tipton, one of the other drivers struck by rocks on April 19, wrote a letter to the court Monday.

“These three have created so many problems for so many people,” he wrote. “Some of us have nightmares on a regular basis, now causing many restless nights.”

Karol-Chik and the third co-defendant, 20-year-old Zachary Kwak, eventually took plea deals with the First Judicial District Attorney. Both plea deals involved testifying against their former friend, Koenig, during the trial.

Karol-Chik pleaded guilty to the aforementioned charges and faced up to 72 years in prison.

Kwak pleaded guilty to first-degree assault, multiple counts of second-degree assault and attempted second-degree assault, with a prison sentence looming between 20 and 32 years. He is scheduled to be sentenced Friday morning.

Karol-Chik’s parents called the man a good child and hard worker who was previously on delayed enlistment for the Marines.

Kristie Karol-Chik, the defendant’s mother, begged the judge to lower the sentence from the maximum of 72 years because Karol-Chik never meant to hurt anyone and was only acting with the underdeveloped brain of a minor, despite being freshly 18 at the time of the death.

Karol-Chik openly sobbed while his parents spoke.

Koenig’s defense during the trial also focused around the defendants’ ages, with Koenig’s defense attorneys bringing in psychologists to talk about how adolescent brains aren’t developed enough yet and that causes them to make rash decisions without fully thinking through consequences.

“He is not a soundbite for the news. He is not a press conference in front of the courthouse. He is not a hateful mean child,” she said, adding that despite everyone in the courtroom hating the family, they had to come support their son.

Karol-Chik, himself, addressed the court before being sentenced, asking Bartell’s family to forgive him, if ever possible.

“Nothing I can say will erase the pain, hurt and fear that I’ve caused,” he said. “Nothing will repair the harm that was done and nothing I say will bring back Alexa Bartell.”

He added that the person he was during those days, heavily influenced by the people around him because of unhappiness himself, is not the person he is today, and he strives to become someone he can be proud of.

Prior to sentencing, Zenisek added that Karol-Chik’s participation in testimony was crucial in finding Koenig guilty, but Karol-Chik was still guilty of his charges.

“His participation in the events — inexcusable — but less destructive than those from the left side of the vehicle,” Zenisek said before sentencing Karol-Chik. “The last event, the one that took the life of Ms. Bartell, so valuable in the community, had a level of violence, destruction and cruelty that is distinct even from the other events of destruction and cruelty of the evening.”