74-year-old Spokane man arrested on suspicion of murder in 1986 cold case

SPOKANE, Wa. (Spokesman-Review) — DNA evidence may have helped solve the 40-year-old cold case killing of a 32-year-old woman who was searching for her runaway teen daughter before she was found strangled in an East Central Spokane alley.

Spokane police arrested 74-year-old David J. Tibbett on Wednesday on suspicion of second-degree murder in the death of Mary Ann Turner, according to a news release from the police department. Detectives on Wednesday served a search warrant on the Spokane home of Tibbett, took him into custody and booked him into the Spokane County Jail around 2:30 p.m.

Officers responded about 7:40 a.m. Nov. 4, 1986, to an alley near South Ivory Street and East Pacific Avenue for a report of a person down in the street, the release said. Officers found a woman, later identified as Turner, dead in the alley. It was evident to investigators she had been murdered, police said.

Detectives used DNA in conjunction with witness statements made early in the investigation to develop probable cause to arrest Tibbett on the murder charge. Police said the arrest was not possible without the Washington State Patrol Crime Lab, Spokane County Prosecuting Attorney’s Office and Othram, a corporation specializing in forensic genetic genealogy to help solve cold cases.

Investigators reported there were signs a minor struggle took place on the ground next to a garage where Turner was found with her scarf and sweater wrapped around her neck, according to a 2023 Spokesman-Review story.

Turner had no money or driver’s license on her, but her boyfriend was able to identify her, according to a Spokane Daily Chronicle story at the time.

The 2023 S-R story indicated that police believed the killer drove Turner, who was known to work as a prostitute, to the area, then drove away. Witnesses spotted Turner getting into a 1970s Ford Torino at about 2:30 a.m. in the area known then for prostitution.

Turner’s death followed the 1980s deaths of Debbi Finnern and Ruby Doss, both of whom were sex workers. DNA evidence linked Richard Aguirre, a former Pasco police officer, to Doss’ killing. Aguirre was found guilty of her murder in 2023 and sentenced the following year to 25 years in prison.

No one has been arrested in the 1984 stabbing of Finnern.

Turner grew up in California and entered foster care at 11 after her mother had a mental breakdown. Her father was hit by a train a year later and died.

She got pregnant at 13 while in foster care. She gave that baby up, but when she got pregnant again at 15, decided to keep her daughter, Manieka.

Turner’s sister, Brenda Lee, took custody of Manieka for a time after Turner had a nervous breakdown at 21.

Turner occasionally turned to sex work to be able to eat, Lee said after Turner’s death.

“It was like a way of survival for her,” Lee said. “If she was down and out then she would do it to tide herself over until her next check came. It was not a regular thing. She did it just to eat.”

Turner worried when Manieka ran away at 16. She desperately tried to look for her, but Manieka was found later in Seattle. She attended Turner’s funeral.

Police said the investigation into Turner’s death is ongoing.