After nearly two years of investigation, authorities have arrested the suspect in the 2023 fatal stabbing of 22-year-old Tiara Atencio on Southeast Powell Boulevard in Portland.
The Night of the Tragedy
On the night of October 19, 2023, Portland Police Bureau (PPB) East Precinct officers responded to reports of a stabbing near S.E. Powell Boulevard and 68th Avenue at approximately 11:05 p.m. When officers arrived, they found Atencio gravely injured and bleeding from multiple stab wounds. She was immediately transported by ambulance to a nearby hospital but, despite medical efforts, succumbed to her injuries shortly after arrival.
The medical examiner later confirmed that Atencio’s cause of death was due to stab wounds, officially ruling her death a homicide.
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The Long Search for the Suspect
Detectives from PPB’s Homicide Unit quickly began investigating and developed leads regarding a potential suspect. However, despite early progress, no arrests were made, and the case went unsolved for nearly two years.
For Tiara’s family and community, the wait for justice was long and painful. Yet, investigators continued to pursue the case, gathering new evidence and coordinating with out-of-state law enforcement agencies.
Arrest in Montana
On October 13, 2025—just six days before the second anniversary of the murder—authorities announced a breakthrough. Members of the Montana Regional Violent Crimes Task Force, working in collaboration with the Missoula Police Department, arrested 21-year-old Connor Jeremiah O’Brien in Montana.
O’Brien is currently being held in the Missoula County Jail while awaiting extradition to Oregon. He faces two serious charges: Murder in the Second Degree and Unlawful Use of a Weapon.
Due to recent changes in Montana law, booking photos of suspects are no longer released to the public, so no mugshot of O’Brien is available at this time.
Continuing the Investigation
While the arrest marks a major development, Portland Police continue to seek any additional information related to the case. Detectives urge anyone who may have seen or heard anything near S.E. Powell Boulevard and 68th Avenue on the night of October 19, 2023, or anyone with information about Connor O’Brien’s actions, to come forward.
Tips can be submitted to the Portland Police Bureau Homicide Unit, ensuring that any remaining details that could help bring full justice for Tiara Atencio are shared.
After nearly two years, the arrest offers hope to Atencio’s loved ones and the Portland community that closure may finally be within reach.
