Teen pleads guilty in rock-throwing shooting spree in Colorado that killed 20-year-old driver

One of three Colorado teenagers charged in connection with a rock-throwing spree that killed a 20-year-old driver last year has pleaded guilty as part of a plea agreement, officials said Friday.

Seven vehicles were hit by large boulders on the night of April 19, 2023. Three people were injured and one – Alexa Bartell, the final victim – was killed, prosecutors said.

Three seniors, then 18, were charged with 13 counts in connection with the incident – including first-degree murder with extreme indifference.

One of the teens – Zachary Kwak, now 19 – pleaded guilty Friday to three new charges related to the rock-throwing attack, according to the Colorado First Judicial District Attorney’s Office, which is prosecuting the case.

Kwak pleaded guilty to first- and second-degree assault and criminal attempt to commit second-degree assault. The original charge against Kwak was dismissed because of his plea, prosecutors said.

“As part of today’s plea, Kwak agreed that, in light of Bartell’s death, the defendant acted knowingly and under circumstances that demonstrated extreme indifference to the value of human life by engaging in conduct that posed a serious risk of death,” the Colorado First Judicial District Attorney’s Office said in a statement.

Kwak’s lawyers did not comment on the plea deal.

Kwak faces 20 to 32 years in prison as a “result of his pleading and cooperation,” prosecutors said. His sentencing is scheduled for September 3, after the cases of the other two teenagers charged with the rock-throwing, Joseph Koenig and Nicholas “Mitch” Karol-Chik, are resolved.

First-degree murder with extreme indifference carries a mandatory life sentence.

The three teenagers were each tried individually. Karol-Chik’s trial is scheduled to begin June 7, while Koenig’s trial is scheduled to begin July 19.

Both pleaded not guilty to their charges.

Karol-Chik allegedly told police while in custody that all three teens had thrown rocks at cars and were “agitated” when they met her, according to court documents.

When questioned, Kwak allegedly said he took a photo of Bartell’s car because he “thought Joseph or Mitch would want it as a souvenir,” court documents say.

After Bartell’s death, Kwak allegedly said that Koenig and Karol-Chik had talked about being “blood brothers” and that they had agreed never to speak about the incident again, court documents said.