3 suspects to stand trial in June and July for deadly Colorado rock-throwing incident

The three suspects arrested and accused in last year's rock-throwing death of Alexa Bartell appeared in Jefferson County Court on Monday as a judge set their trial dates. 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 to start June 7, Kwak's trial is scheduled to start June 24 and Koenig's trial is scheduled to begin July 19. 

There is no indication whether the suspects will testify against one another, but they engaged detectives to varying degrees during interviews. Karol-Chik told detectives the rock and other object throwing had been going on for months. That included throwing other objects. 

Koenig is now accused of throwing the statue on February 25, meaning the additional charges of attempted assault and murder. Karol-Chik also allegedly told detectives the night of Alexa Bartell's killing, he believed Kwak threw the fatal rock. 

The three were allegedly in the truck and Kwak and Koenig sat in front while he sat in back Karol-Chik reportedly told investigators. Kwak reportedly told detectives Koenig threw the fatal rock. Koenig had said little to detectives in the early stages of the investigation after the arrests last year.

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. The friend, worried about what had happened went in search of Alexa and found her dead.

RELATED: Timeline: A look at the Colorado rock-throwing attacks

Investigators used a so-called "tower dump" of cell phone location data to help them find the suspects in the case. Such data dumps are used more frequently by investigators seeking what phones may be in a given area when a crime is committed. Information from the data helped establish the suspects were in the area at the time of Alexa's killing.  

"The 4th Amendment requires that people be free from unreasonable searches and seizures," noted veteran prosecution and defense attorney Karen Steinhauser. "This isn't settled law." 

Courts have not been fond of wide-ranging tower dumps that net data on many phones unrelated to the case. In effect saying the net is too wide. Investigators typically only seek information on who owns the phones once they focus in on certain ones.

The area of Indiana Street north of Arvada is sparsely populated and has very light traffic late at night when Alexa Bartell was killed. "If they were just asking say... on Broadway between Hampden and downtown, we want all the cars who were around that area, then I think we'd have a problem with being precise and specific," said Steinhauser. 

The fact that the location was not a busy area and timeline was known could well help the court look favorably on the use of the data. 

Prosecution said on Monday that it did not believe the tower dump was a search because people agree to give up their privacy to the mapping service providers and cell phone companies. 

But Steinhauser notes there is a difference between giving that information to the providers and giving that information to the government, which is not necessarily implied.

"I think this is an area that just, we just need to see what happens," said Steinhauser. The question of the use of the tower dumps generally she believes is headed for higher courts. 

"It's going to end up at the state level and I think that it is most likely an issue that is going to end up going even further at our Supreme Court."

Defense in the case asked the judge to review the use of the data and Judge Christopher Zenisek indicated he will rule on motions on May 7.

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.