Colorado suspects in rock-throwing death plead not guilty, trials to begin this summer

The three suspects arrested and accused in last year's rock-throwing death of Alexa Bartell appeared in Jefferson County Court on Monday. All pleaded not guilty to more than a dozen charges. 

The 20-year-old was struck and killed in April of last year after she was struck by a rock that was thrown into her windshield. Several others were injured in similar incidents with what authorities described as "large landscaping rocks."     

Joseph Koenig, Nicholas "Mitch" Karol-Chik and Zachary Kwak are each facing 13 charges, including murder and attempted murder charges, in connection with rock-throwing attacks that killed Alexa Bartell and injured others. On Monday, the court tacked on four additional charges, including attempted murder and assault, for Koenig after two more victims came forward in connection to an incident that happened on Feb. 25, 2023. 

Investigators believe there were a total of 10 vehicles involved in at least three different incidents regarding the suspects. 

They will be tried separately. Karol-Chik's trial is scheduled for June 7, 10-14, 18, 20-21; Koenig's trial is scheduled for July 19, 22-26, July 30 through Aug. 1; Kwak's trial is scheduled for June 24-28, July 2, 3, 5. 

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Bartell, of Arvada, was killed late at night on April 19, 2023, when a rock crashed through her windshield as she was driving on the 10600 block of Indiana Street close to the Jefferson County and Boulder County lines. Her vehicle left the roadway and ended up in a field. She was on the phone talking to a friend when she was struck and the phone went silent.  

All of the suspects were 18 years old and seniors in high school at the time of their arrests. One attended Ralston Valley High School, one Standley Lake High School in Westminster, and the other attended online school.