Spokane police have arrested a 74-year-old man in the 1986 strangling of Mary Ann Turner, a 32-year-old mother who was killed while searching for her runaway teenage daughter. Detectives served a search warrant at David J. Tibbett's Spokane home on Wednesday, October 21, and booked him into the Spokane County Jail on suspicion of second-degree murder, The Spokesman-Review reported.
Tibbett is presumed innocent. The reports reviewed for this story did not say whether he has entered a plea or who represents him. He is being held on a $1 million bond, the paper reported.
A death in East Central
Officers found Turner's body in an alley near South Ivory Street and East Pacific Avenue early on the morning of November 4, 1986. Her scarf and sweater were wrapped around her neck. In 2023, the paper reported that investigators saw signs of a brief struggle beside a garage and believed the killer had driven her there. Witnesses saw her get into a mid-1970s Ford Torino around 2:30 a.m.
Turner's life had been hard. Raised in California, she entered foster care at 11 after her mother's breakdown, and her father died a year later. She had her daughter, Manieka, at 15, and later struggled with mental illness. Her sister, Brenda Lee, said Turner sometimes turned to sex work to get by. "She did it just to eat," Lee said. When Manieka ran away at 16, Turner came to Washington to find her. Manieka was later found in Seattle and attended her mother's funeral.
For decades the case stalled. A 1998 task force reviewed 18 unsolved deaths of women in the area since 1984, including Turner's. Police saw "commonalities" with other cases but nothing solid. "It's not enough to hang your hat on," Sgt. Gene Ziegler said at the time.
The tip and the envelope
Police say DNA evidence, combined with witness statements from early in the investigation, gave them probable cause. According to court records described by the Spokesman-Review, a confidential caller to the old Secret Witness tip program named Tibbett as a possible suspect back then, saying he drove a vehicle similar to the one Turner was last seen getting into. Records say he drove a bronze 1986 Ford Elite registered to his East Decatur home, the same house where he was arrested.
Investigators then mailed Tibbett a letter asking him to return a confirmation that his stolen car had been recovered. DNA from the glue seal on the returned envelope matched male DNA found under Turner's fingernails, according to court records.
Police said the arrest would not have been possible without the Washington State Patrol Crime Lab, the Spokane County Prosecuting Attorney's Office and Othram, a Texas company that uses forensic genetic genealogy and genome sequencing on degraded DNA samples.
Questions for the defense
Ruse letters like this one are a familiar investigative tactic, and they are often the first thing a defense lawyer examines, since the person never knowingly agreed to a DNA test. A match under fingernails can show contact. By itself it does not show when that contact happened or what it meant, which is where a defense would likely focus. Those questions get sorted out in pretrial motions and, if the case gets there, in front of a jury.
Police are also looking at whether Tibbett may be linked to the deaths of other women, the Spokesman-Review reported. Turner's death followed the 1980s killings of Debbi Finnern and Ruby Doss. A former Pasco police officer, Richard Aguirre, was found guilty in 2023 of killing Doss after DNA tied him to the case and was sentenced the following year to 25 years in prison. No one has been arrested in the 1984 stabbing of Finnern.
Detectives are asking anyone who called Secret Witness about the case, or who ran the program and took calls, to come forward. "We encourage anyone to come forward, even if the detail seems insignificant," police said in a release. Labs now sit at the center of investigations old and new, from this one to the open search for Nancy Guthrie. It is the kind of case the Two Taps legal panel takes apart on the show.
Two Taps News stories summarize reporting and the analysis discussed on Two Taps and Friends. They are not legal advice. Read our standards.
