Colorado Governor Jared Polis appointed Kathleen M. Tierney to the Arapahoe County Court in the 18th Judicial District. The appointment is effective February 16, 2026, and fills a vacancy created by the retirement of the Honorable Michael J. Roche. 

Tierney is a Senior/Assistant Chief Deputy District Attorney in the 18th Judicial District Attorney’s Office, a position she has held since 2024. Her practice consists of criminal prosecution.

Previously, she was a Deputy District Attorney in the 18th Judicial District Attorney’s Office (2021-2024) and Deputy District Attorney in the 2nd Judicial District Attorney’s Office (2019-2021).

Tierney earned her B.A. from the University of Scranton in 2015 and her J.D. from Penn State Dickinson Law in 2018.

Colorado’s 18^th Judicial District covers Arapahoe County.