GOLDEN, Colo. (KDVR) — The three teenagers charged with throwing a rock at a moving car and killing a 20-year-old woman were granted a delay at their preliminary hearing Friday afternoon.

Nicholas “Mitch” Karol-Chik, Joseph Koenig and Zachary Kwak each face 13 counts, including first-degree murder for the death of Alexa Bartell.

Bartell was killed on the night of April 19 when a rock was thrown through the windshield of her car while she was driving through Jefferson County. At least four other rock-throwing incidents were reported that night.

Detectives with the Jefferson County Sheriff’s Office used cell phone tracking data to find their suspects.

Earlier this week, Jefferson County prosecutors added additional charges of attempted murder and assault against Karol-Chik and Koenig after investigators say they threw a statue-like object at a moving car on April 1.

In court Friday afternoon, prosecutors acknowledged they had looked at two similar incidents but ultimately didn’t feel like they had enough evidence to add more charges.

At the time of the arrests in late April, Karol-Chik allegedly told detectives he and Koenig had thrown rocks at cars on at least 10 occasions dating back to February.

Cell phone data and OnStar records tied to Koenig’s truck will be key evidence, but defense attorneys for Koenig said they had only received some of the evidence in the past two weeks and would need special software to review it.

Upon hearing that, Judge Christopher Clayton Zenisek agreed to delay the preliminary hearing until Oct. 18.

Prosecutors opposed the delay, saying they could prove they had probable cause for the arrests without relying on evidence recently provided to the defense. Prosecutors also said family members of the victim had flown in from out of state for the hearing as part of their argument against the delay.