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Alexa Bartell
Alexa Bartell of Arvada. (Handout)

Three 18-year-old men were arrested overnight Tuesday in a rock-throwing spree west of Denver last week that killed 20-year-old Alexa Bartell and injured several other people.

The suspects — Joseph Koenig, Nicholas “Mitch” Karol-Chik and Zachary Kwak — were taken into custody at their Arvada homes, the Jefferson County Sheriff’s Office announced Wednesday morning. The three face charges of first-degree murder with extreme indifference.

The teens are suspected of throwing large landscaping rocks at a string of cars shortly after 10 p.m. on April 19 in Westminster, officials said, and Bartell’s car was the last car struck.

Additional charges are expected to be filed by the First Judicial District Attorney’s Office, the sheriff’s office said.

The sheriff’s office called Bartell’s family to notify them of the arrests early Wednesday, Jacki Kelley, a spokesman for the Jefferson County Sheriff’s Office, said during a news conference Wednesday morning.

“They’re just so grateful,” Kelley said. “They are still suffering from the greatest loss possible, but this is the beginning of the journey that they will be on next and they are incredibly grateful that these suspects are at least identified and brought to justice for what they have done.” 

Investigators identified a black 2016 Chevy Silverado as the car the suspects were inside as they threw the rocks.

The arrests came days after investigators sent out calls for any eyewitnesses to the rock-throwing attacks to send tips, including asking Tesla owners to check their footage for any evidence. Tesla cars are constantly recording while in motion.

Map of rock throwing incidents
A map released by the Jefferson County Sheriff’s Office shows the location of seven spots where vehicles were allegedly hit by a rock. The spot marked “7” is the location where 20-year-old Alexa Bartell was killed. (Jefferson County Sheriff’s Office image)

Bartell, 20, died after a rock flew through her windshield while driving on Indiana Street at about 10:45 p.m. on April 19.

She was talking on the phone with a friend while driving when she was hit by the rock, investigators said. After the call went silent, the friend tracked Bartell’s location with a phone app and found her dead in her car, which had crashed into a field. 

In addition to Bartell’s death, drivers of two other vehicles suffered minor injuries. 

Olivia Prentzel

Olivia Prentzel is a general assignment writer for The Colorado Sun. Email: