On Nov. 4, 1986, Spokane (Washington) police officers responded to an alley for a report of a person down in the roadway. Upon arrival, the officers discovered a deceased female nearby. The female was identified as 32-year-old Mary Ann Turner, and it was evident to investigators she had been murdered.
The Spokane Police Department launched an investigation, but the person responsible for Turner’s murder could not be identified.
In August 2025, investigators with the Spokane Police Department submitted evidence to Othram for advanced DNA testing. Using Forensic-Grade Genome Sequencing, Othram scientists worked to develop a comprehensive DNA profile for the suspect. This profile was used by Othram's forensic genetic genealogy team to develop new leads in the case.
These leads were provided to law enforcement for a follow-up investigation. After investigating for nearly four decades, detectives developed probable cause to charge 74-year-old David Tibbett with Second Degree Murder through DNA evidence in conjunction with witness statements made early in the investigation.
On Oct. 21, 2026, detectives with the Major Crimes Unit (MCU) and Special Investigations Unit (SIU) served a search warrant on the home of Tibbett. Tibbett was taken into custody and booked into the Spokane County Jail.
The investigation into the death of Mary Ann Turner is still ongoing. The Spokane Police Department is seeking information from the public about this case. Even if you’ve spoken with investigators before, please reach out if you have anything to share. Including any of those who called in as secret witnesses or administered that program.
Someone may have information they did not recognize as important at the time or may have information they have yet to share with investigators. We encourage anyone to come forward, even if the detail seems insignificant.
Data from Spokane Police Department