Overview
- O’Brien is accused of second-degree murder and unlawful use of a weapon in the 2023 killing of 22-year-old Tiara Atencio.
- Portland police say he fled after the Oct. 19 stabbing on Southeast Powell Boulevard, and Atencio later died at a hospital.
- The Montana Regional Violent Crimes Task Force and the Missoula Police Department made the arrest in Missoula.
- Missoula police said their officers worked with the Montana FBI during the arrest, and O’Brien is lodged in the Missoula County Jail.
- Portland police say the investigation remains active and request tips from the public, and Atencio’s family has been notified of the arrest.