Arrest made in cold case sexual assault in northern Arizona community
Thomas Martin Duke (Courtesy: Pinetop-Lakeside Police Department)
PINETOP-LAKESIDE, Ariz. - Police in a northern Arizona community say they have made an arrest in a sexual assault case that happened decades ago.
The Pinetop-Lakeside Police Department reopened the case almost a year ago and Pinetop-Lakeside Detective Ricky Bunch says advancements in DNA technology were a game changer.
Thomas Duke, the suspect in this case, served just over six years in an Arizona prison in the late 70s and early 80s for two rapes and an attempted rape.
Now, he has been tied to two other sexual assaults, with investigators building their case to get closure for the victims.
Per a statement released by the Pinetop-Lakeside Police Department, Thomas Martin Duke of San Tan Valley was identified as the suspect in the case, and he was indicted by a grand jury in Navajo County on charges of kidnapping, sexual assault, and sexual abuse.
Thomas Duke, Navajo County Sheriff's Office mugshot
"He was extradited and is in the custody of the Navajo County Jail," read a portion of the statement.
Bunch reopened the 1988 kidnapping and sexual assault of a gas station clerk in Pinetop near the end of 2023.
"There was a lot of work that was done back in the 80s, but obviously they're kind of limited by the technology that they can do," he said.
Detective Bunch says while DNA evidence could be tested in 1988, the sample size needed to be much larger than today.
"For example, you know, we can get DNA nowadays off somebody touching something. We can potentially get a DNA profile off of that. Back in the 80s, they might've needed a puddle of blood," said Bunch.
He said the lucky break in the case happened because the evidence collection was done so well in 1988. It led to a positive match for Thomas Duke, who was not previously on investigators' radar for this crime.
Police accuse Duke of kidnapping a female gas station clerk on the morning of December 16, 1988, threatening her, and forcing her into his car.
"The suspect is alleged to have then violently sexually assaulted her and left her in the woods," police said in the statement.
Duke is accused of then leaving her in the woods before she was able to find a nearby home and call 911.
According to the Navajo County Attorney's Office, DNA results also tie him to a 1997 sexual assault in Mesa.
Back in Maricopa County, extensive work has been done to reduce the backlog of sexual assault kits.
The Phoenix Police Department implemented a "test all" police in the state of Arizona that allowed kits processed beginning in 1978 to be analyzed under new technology.
In September 2023, Phoenix Mayor Kate Gallego and the city council agreed to allow the outsourcing of sexual assault kits.
The decision helped clear a backlog of 80 kits pending while the city estimates that 50 new kits arrive each month.
They said in a release that over 6,000 kits have been tested over the last eight years.
Bunch says he was relieved to get a break in the case, a feeling he says was also felt by the victim.
"I think it was a pretty big surprise when I contacted her, but you know, hopefully now that she knows who did this and it's going to go through the court process, which unfortunately can take awhile, she can get some closure at the end of it," Bunch said.
Thomas Duke's release hearing is scheduled for December 19.
Detective Bunch is still actively working this case and wants anyone with information that may help in a future trial to contact the Pinewood-Lakeside Police Department and ask for him or call the WeTip anonymous hotline.