Three high school seniors were arrested after allegedly hurling a landscaping rock at a Colorado woman, killing her as she drove just outside of Denver, authorities said Wednesday.
Alexa Bartell, 20, “was killed when a rock was thrown through her windshield as she was driving” north in the 10600 block of Indiana Street at about 10:45 p.m. in Westminster on April 19, according to a statement from Jefferson County Sheriff’s investigators.
Bartell was the last of several cars “struck by large landscaping rocks in a spree that began shortly after” 10 p.m. that night near 100th Avenue and Simms Street in Westminster, officials said.
Joseph Nicholas “Mitch” Karol-Chik, Joseph Koenig and Zachary Kwak, all 18, were taken into custody at their homes in Arvada, according to the sheriffs statement.
All three suspects are 12th graders from Jefferson County Public Schools — one who attends Ralston Valley HS, one from Standley Lake HS while a third is enrolled in an online program, said sheriff’s spokesperson Jacki Kelley, who didn’t know which teen goes to which school.
A rep for Jeffco Public Schools could not be immediately reached for comment on Wednesday.
The rock thrown by suspects is what killed Bartell and not any subsequent crash, officials said.
“The rock came through Alexa Bartell’s windshield, striking and killing her,” Kelley told NBC News on Wednesday. “The rocks that we have described in this crime series are all about 4 to 6 inches in size and about 3 to 5 pounds a piece. They’re large boulder landscaping rocks.”
The suspects were traveling in a black 2016 Chevy Silverado that night, though it wasn’t immediately clear who was driving or threw the rock that killed Bartell, officials said.
“We believe the vehicle was traveling in the opposite direction as our victims,” Kelley said.
The three suspects were booked on suspicion of first-degree murder by extreme indifference, according to the sheriff.
While first-degree murder is typically associated with an intended victim and motive, Colorado’s extreme indifference statute is meant for defendants who aimed to kill someone —but just not a targeted individual, University of Colorado clinical law professor Ann England said.
“Pulling out an AK-47 and shooting into a crowd of people, then there’s no doubt that you intended to to kill,” even if not targeting a specific individual, England said.
“Throwing a rock (and charging first-degree murder) is going to be hard. I mean is throwing a rock a known risk (to possibly kill someone)? Throwing a rock at a moving car, now that someone has died, it seems obvious, right? But before that? I’m not totally sure.”
It wasn’t immediately clear if the three men had hired or been assigned criminal defense lawyers to speak on their behalf.
Phone calls to publicly listed phone numbers for Colorado relatives of Kwak and Karol-Chik went unanswered on Wednesday.
The three teens were expected to make their first court appearance on Thursday morning.
This article was originally published on NBCNews.com.