A judge Thursday sentenced a Jefferson County man to 45 years in prison after he pleaded guilty to second-degree murder in the April 2023 rock-throwing death of 20-year-old Alexa Bartell.
Wearing a lime-green jail jumpsuit with his hands shackled at his waist, Nicholas “Mitch” Karol-Chik, 20, accepted his penalty in silence.
“This was a pattern of conduct, not only on this night but other nights, as well,” First Judicial District Court Judge Christopher Zenisek said in handing down a sentence in the midrange of the 35 to 72 years the defendant had faced.
Karol-Chik, along with two other defendants in the case, Nicholas Koenig and Zachary Kwak, were all charged with first-degree murder with extreme indifference after Bartell was killed by a landscaping rock that was thrown through her windshield from their truck while they sped down a road west of Denver.
As part of a plea deal with prosecutors, Karol-Chik and Kwak testified last week that Koenig threw the 9.3-pound rock that killed Bartell. In exchange for their testimony, murder charges against the two were dismissed. A jury found Koenig guilty of first-degree murder.
Karol-Chik also pleaded guilty to attempted first-degree murder for nine other drivers who were injured in the string of attacks, in which rocks narrowly missed the head of one driver and flung shattered glass into the eyes of others.
The sentencing came after Karol-Chik apologized in court, saying he acted out of a desire to impress people he thought were his friends, worried that he’d be cast out if he didn’t go along with the rock-throwing spree, which began in February and ended the night Bartell was killed.
“The most important thing I can say today is how truly sorry I am,” Karol-Chik said. “Every day I wish I could turn back time and change everything that happened.”
Prosecutors requested a penalty at the top end of the range.
Brynn Chase, a deputy district attorney, acknowledged that Karol-Chik’s testimony was “undeniably a key component of the evidence against Koenig at trial.” But she also said the crime wouldn’t have happened if Karol-Chik hadn’t passed the fatal rock to Koenig moments before Koenig threw it “like a shot put” through Bartell’s windshield. The rock hit her in the head, killing her instantly and sending her car careering off the road.
“Mr. Karol-Chik has a very high level of culpability that is very close to Mr. Koenig’s,” Chase said.
A defense attorney, Holly Gummerson, requested a 35-year sentence, emphasizing that Karol-Chik was 18 years old at the time of the crime, calling him “an emerging adult” with “an underdeveloped brain” who didn’t fully understand the consequences of his actions or the risks they posed to others.
Throwing rocks at cars was an impulsive, “childish” act that an adult wouldn’t be expected to engage in, Gummerson said.
“This entire case is a tragedy,” she told the court.
Before the sentence was imposed, several of Bartell’s family members took turns offering wrenching tributes to the woman, describing her as kind, caring and excited for the future. Each asked the judge to impose a stiff penalty.
“What happened to Alexa wasn’t a prank,” said Erin Miller, her cousin. “It was a reckless and deliberate act that not only ended her life but shattered the lives of those who loved her.”
Through tears, Greg Bartell called himself the grieving father of a “loving, kind, caring, thoughtful, fun, intelligent young lady.”
“Alexa was my everything in life,” he said, standing next to a photograph of the victim. “She was my pride and joy. She was a beautiful person inside and out.
“My heart is completely shattered, and will remain that way the rest of my life.”
Her mother, Kelly Bartell, said her daughter had an infectious personality and natural kindness that “made others feel safe to be who they are, too.” In a halting voice, she recounted “the brutal reality I will never again hold my daughter in my arms.”
“Each morning I wake up and relive the same nightmare,” she told the court. “There is no remorse, no humanity in what they did.”
Kwak, who also testified against Koenig as part of a plea deal, is set to be sentenced Friday. He faces 20-32 years in prison.
Koenig, who faces life in prison without the possibility of parole, will be sentenced in court June 3.