Tacoma detectives investigate theory, partial evidence of male suspect in unsolved 2020 murder

Detectives with Tacoma Police Department are bringing new attention to unsolved murders. Each month, investigators will publicly highlight a cold case to help learn new details that could lead to an arrest. Friday launched the new initiative and the first case was that of Diana Davis, a mother of two who was killed in the summer of 2020.

Davis worked as a caregiver in Tukwila. Police explained Davis lived part-time in Auburn and Tacoma. Investigators said she left her Auburn home to tend to her vegetable plot at a community garden in Tacoma on July 27, 2020. She then went to a small hardware store in Tacoma for 45 minutes and left without buying anything. From there, Davis drove to an area near Lumen Field in Seattle where her cellphone signal was last located. By that evening, the phone was turned off. 

On July 29, investigators said her car was found burning in alley in Tacoma with her purse inside. Detectives soon learned her family already filed a Missing Persons Report. Days of searching for Davis came to a painful end on August 5, when investigators said her body was found buried in the woods at Snoqualmie Pass.

"Who could have done this? Who could have done this and why?" said Monica Joseph, Diana’s best friend of nearly 40 years. "I couldn’t believe it at first. I was like no, there has got to be an explanation."

Detective Jack Nasworthy is the lead investigator on Davis’ case. He said he has been with Tacoma Police Department for 31 years, and in the Homicide Unit since 2011. Nawsworhty said Davis’ murder is "definitely unique."

"This person went through a lot of effort to cover up this crime. Not only did they take her out in the woods, bury her in a place where they probably didn’t think she’d ever be located. But they also went through the effort to burn her car to hide evidence. And that’s not something you’re going to see usually in a random crime," said Nasworthy.

The detective said it took several days to confirm a positive identification on Davis because of the condition her body was found in. He explained extensive forensic analysis revealed Davis died from multiple blunt force injuries to her face.

Though loved ones have questioned why the mother of two traveled from Tacoma to Seattle, Nasworthy said there is a possible answer.

"One of the things that we did find out through the investigation is that Diana did meet men on dating websites. And our working theory is that she had arranged to meet somebody in Seattle the night that she disappeared," said Nasworthy.

Body found near Snoqualmie Pass identified as missing woman whose car was found on fire

A body found near Snoqualmie Pass this week has been identified as a Washington woman who has been missing since late July.

He said Washington State Patrol helped discover partial evidence of a male suspect. Through search warrants, Nasworthy said his team contacted at least one dating website, but Davis’ last login on that page was more than a month prior to her disappearance. In the search for the killer, investigators hope to learn where else Davis was logging in online, and who else she was talking to.

"Seek out information from the public about anybody that might know contacting her in the past—like, ‘When I talked to her, this is the dating website that we talked on,’" said Nasworthy. "See if anyone can let us know these are the websites she was using, this is who she was talking to."

Crime Stoppers is rewarding up to $1,000 dollars for information that leads to an arrest in Davis’ death. Tips can remain anonymous by calling 1-800-222-TIPS.

Joseph said she and Davis were close ever since they were 13-years-old. The best friend said they talked about everything all the time. When their conversations suddenly stopped in July 2020, she learned days later the shocking fate of her dear friend. 

"I think about her every single day," said Joseph. "She couldn’t even harm a fly. So, for someone to do this to her, to take her life the way that they did it’s just…it’s really difficult to process."

Now Joseph is one of many people using their voice to seek justice for Davis. She is asking those who know something about Davis’ death to speak up.

"Diana deserves justice. And what happened to her she didn’t deserve it," she said. "It’s just time for this to come to an end."

Anyone with information is asked to call Crime Stoppers. You can remain completely anonymous and could be eligible for a $1,000 cash reward. The number is 1-800-222-TIPS(8477). You can also submit a tip using the P3 Tips app on your smartphone.