What started as a spree of large landscaping rocks being thrown at cars in Westminster, Colorado took a deadly turn last week when Alexa Bartell, 20, was killed by a rock that was thrown through her windshield. The incident occurred just outside Denver on April 19th when Bartell was driving north on Indiana Street. She was the last car to be hit by a large rock, and one of several that were pelted that evening. The spree started just after 10 pm that night. Yesterday, three men, all 18, were arrested in connection to the incident: Joseph Koenig, Nicholas “Mitch” Karol-Chik, and Zachary Kwak. All three men are suspected of throwing rocks, but it is not yet clear who was driving or who threw the fatal rock. The suspects are facing charges of first-degree murder by extreme indifference. The Jefferson County Sheriff's Office coordinated with the Westminster Police, Arvada Police and the Boulder County Sheriff's Office to identify and arrest the suspects. It remains to be seen if there will be additional charges, but investigators thanked the public and media for their help in making the arrests.