
Colorado jury finds Joseph Koenig guilty of first-degree murder in deadly rock-throwing trial
26. April 2025
Jurors have delivered a guilty verdict for first-degree murder for Joseph Koenig, the Colorado man accused of throwing a rock through the windshield of Alexa Bartell’s moving vehicle, killing her. Deliberations began Thursday, with the jury returning the verdict less than two hours after returning to deliberate on Friday morning.
Jefferson County
Koenig was charged with first-degree murder in Bartell’s death, as well as nine additional criminal counts of attempted first-degree murder for allegedly throwing rocks at other vehicles. There were also three counts of second-degree assault and six counts of attempted second-degree assault for a total of 19 counts.
The jury returned guilty verdicts on all charges, although some were downgraded to lesser charges, including one count of attempted first-degree murder that was downgraded to attempted second-degree murder. Two counts of attempted first-degree murder were downgraded to attempted reckless manslaughter, and another count was downgraded to reckless endangerment.
All counts of second-degree assault were downgraded to third-degree assault. Some of the counts of attempted second-degree assault were downgraded to attempted third-degree assault.
Witnesses testified last week, sharing their experiences that night as they became victims of the rock-throwing attacks.
CBS
Two co-defendants, Nicholas “Mitch” Karol-Chik and Zachary Kwak, pleaded guilty last year for their roles in the 2023 attack. Last week, both men testified against Koenig as part of their plea agreements. Both claimed that it was Koenig who threw the rock that killed Bartell. The defense questioned Karol-Chik’s testimony, pointing to previous interviews where he claimed Kwak had thrown the last rock of the night.
Koenig did not testify. Instead, his defense called behavioral health researcher and Temple University professor Laurence Steinberg to the stand. The defense stressed that Koenig wasn’t fully aware of the consequences of his actions. Steinberg was cross-examined for several hours as District Attorney Katharine Decker sought to establish that adolescents are capable of impulse control and logical reasoning.
CBS
Koenig’s trial, initially scheduled to begin last summer, was delayed for a court-ordered evaluation after his attorneys raised concerns about an ADHD diagnosis.
Closing arguments were heard Thursday morning. The defense asserted that what Koenig did was manslaughter, not murder.
“Did he make a lot of bad decisions? Yes. Knowingly and intentionally,” one prosecutor said.
Koenig’s defense didn’t argue that he didn’t commit a crime but pleaded that the jury find him guilty of a reckless manslaughter charge.
“You’re right. What Joe Koenig did was a crime. He is guilty. We’re asking you to find him guilty of what he did.”
AAron Ontiveroz / AP
Sentencing for Koenig has been scheduled for 8:30 a.m. on June 3. Victims and their families are expected to speak at the sentencing.
Sentencing hearings for Karol-Chik and Kwak have been scheduled for next week, May 1 and May 2, respectively, after the verdict in Koenig’s trial.