The Jefferson County Sheriff's Office says it will likely recommend felony charges against three Colorado elementary school students -- one an 11 year old and two others who are both 10 years old -- after they allegedly threw multiple large rocks from their school bus that then hit a car passing in the other direction.

"It's disturbing. It's absolutely not funny," said Jefferson County Sheriff's Public Information Officer Jacki Kelley. "It's not a prank. It's criminal and it won't be tolerated."

She called the incident "eerily similar" to the 2023 rock throwing incident that killed Alexa Bartell. In that case, three men were in a speeding truck when one threw a landscaping rock that smashed through Bartell's windshield and killed the 20-year-old woman.

The most recent incident occurred May 8 when the boys were headed to school on a Jefferson County Public Schools bus. According to investigators, two rocks were thrown from the bus at a car passing in the other direction. The rocks were "described to me as 6 inch boulders or landscaping rocks," said Kelley.

She said one bounced off the car but another struck with such force that it became lodged in the car's radiator.

The woman driving the car was not hurt, but her car received substantial damage, according to Kelley.

"She stopped," said Kelley, "picked up one of the rocks, turned around and followed the bus to school."

It had gone to Kyffin Elementary School in Golden, where Jeffco Public Schools staff members examined video from onboard cameras and were quickly able to identify the boys.

The Jefferson County sheriff says when it presents its case to the district attorney, it will recommend felony criminal mischief charges against all three, along with charges of reckless endangerment -- a misdemeanor.

"We're disturbed this is happening again," said Kelley. "It's not a prank and it won't be handled that way in Jeffco if this should happen again."

Parents of Kyffin students were notified of the incident via a letter from the school principal May 8. Pam Virden wrote that there had been "recent inappropriate behavior on your student's bus. We have received multiple reports about students throwing items out of the bus windows," said the letter. It did not mention the items were rocks. "This behavior is unacceptable," reads the letter, which says the school took disciplinary action.

A school district spokesperson said "the purpose of the letter was to provide enough information so that families could have a conversation with their children about appropriate behavior. The point was to reiterate what is expected of students when on the bus, not the incident itself."

Asked if the May 8 case might be a "copycat" case stemming from publicity around the Bartell court proceedings, Kelley said she did not know but said "Anyone throwing projectiles at a driver of a moving vehicle should understand the potential consequences of doing that."