Verdict reached in Joseph Koenig case, accused of hurling a rock that killed a young woman on a ‘deadly joyride’

A Colorado jury has declared Joseph Koenig guilty of first-degree murder for his involvement in a deadly rock-throwing incident that claimed the life of 20-year-old Alexa Bartell in April 2023, according to the AP. The conviction marks the culmination of a case that has drawn widespread attention due to its tragic circumstances and the young ages of those involved.​

Koening made a “whoop” sound, one witness said

BREAKING: Jurors find man guilty of murder in Jeffco rock-throwing spree that killed Alexa Bartell https://t.co/Wnzj3Xighq

— The Denver Post (@denverpost) April 25, 2025

On the night of April 19, 2023, Koenig, now 20, and his friends, Nicholas Karol-Chik and Zachary Kwak, were driving through Jefferson County, Colorado, when they began hurling large landscaping rocks at passing vehicles. 

Traveling at speeds up to 80 mph, the group targeted at least seven cars within 45 minutes. Tragically, one of these rocks smashed through the windshield of Alexa Bartell‘s vehicle, striking her in the head and causing fatal injuries. Reports say Bartell’s car veered off the road into a field, where a concerned friend discovered her body using phone tracking.​ Bartell was 20-years old when she died.

Karol-Chik reportedly testified Koening made a “whoop” sound when the rock hit Bartell’s car. The then-teenagers checked on the vehicle, but didn’t call for help, and even took a “memento photo” of the crash, the prosecution alleged.

Koenig lives with borderline personality disorder, his defense said

Joseph Koenig, 20 has been found GUILTY of First-degree murder for throwing rocks at moving vehicles including one that killed 20-year old Alexa Bartell in 2023. He was also found GUILTY OF 18 other charges including 9 counts of attempted murder, 3 counts of 2nd-degree assault,… pic.twitter.com/Lq0F4Jt2Mg

— Seeking Justice (@Seekers4Justice) April 25, 2025

Following their arrests, all three individuals faced multiple charges, including first-degree murder. Koenig’s co-defendants, Karol-Chik and Kwak, accepted plea deals and testified against him. Karol-Chik admitted to handing Koenig the rock that killed Bartell, while Kwak pleaded guilty to first-degree assault and other charges. 

Koenig’s defense argued that he suffered from borderline personality disorder and lacked intent to kill, suggesting a manslaughter conviction instead. However, the jury found Koenig guilty of first-degree murder, emphasizing the extreme indifference to human life demonstrated by his actions.​

Koenig’s sentencing is expected in June

Koenig, scheduled to be sentenced on June 3, 2025, faces a mandatory life sentence. Karol-Chik’s plea deal could result in a prison term of 35 to 72 years. Meanwhile Kwak faces 20 to 32 years. The Bartell family has expressed profound grief over the loss of Alexa. They have described the incident as a senseless act that has forever altered their lives.​