DNA From Discarded Gum Results in Conviction in 1980 Oregon Homicide

Ultimately, it was a discarded piece of chewing gum, casually spit on the bottom in 2021, that was the important thing to fixing the cold-case homicide of a faculty scholar that had confounded the authorities in Oregon for greater than 4 many years.

Robert Arthur Plympton had been beneath police surveillance for the reason that authorities decided that 12 months that he was a “likely contributor” to a DNA profile developed from swabs taken from the physique of Barbara Mae Tucker, who was 19 when she was murdered on the Mount Hood Neighborhood School campus in 1980.

On Friday, Mr. Plympton, 60, was discovered responsible of murdering Ms. Tucker after a three-week bench trial in Portland, Ore. In response to The Oregonian, which reported on the investigation and Mr. Plympton’s conviction, it was the oldest cold-case murder in Gresham, Ore., east of Portland.

On the evening of Jan. 15, 1980, Ms. Tucker was anticipated at a category on the faculty, the place she was finding out enterprise. She by no means arrived.

College students on their solution to class the subsequent morning discovered her “partially clad” physique on a shrub-covered slope close to a campus parking zone, The Oregonian reported on the time. There have been indicators that Ms. Tucker had been sexually assaulted, and that she had struggled along with her assailant.

For many years, the authorities have been unable to determine a suspect or make an arrest.

Step one towards a breakthrough within the case got here in 2000, when vaginal swabs that had been taken throughout Ms. Tucker’s post-mortem have been despatched to the Oregon State Police Crime Lab for evaluation. Lab technicians have been then in a position to develop a DNA profile from the swabs.

In 2021, Parabon NanoLabs, a Virginia firm whose providers embody DNA-based forensics, recognized Mr. Plympton as “a likely contributor to the unknown DNA profile developed in 2000,” the Multnomah County district legal professional’s workplace said in a statement. It was not clear how the DNA connection was made; the district legal professional’s workplace didn’t instantly responded to a request for touch upon Tuesday.

Detectives with the Gresham Police Division discovered that Mr. Plympton was dwelling in Troutdale, Ore., east of Portland and northeast of Gresham, and commenced surreptitiously watching him, prosecutors stated.

When investigators noticed Mr. Plympton spit a bit of chewing gum onto the bottom, they collected it and submitted it to a state police crime lab, prosecutors stated.

“The lab determined the DNA profile developed from the chewing gum matched the DNA profile developed from Ms. Tucker’s vaginal swabs,” the district legal professional’s workplace stated.

Mr. Plympton was arrested on June 8, 2021, as he was driving away from the Troutdale house he shared along with his spouse and son, The Oregonian reported.

He had a prison document, together with a conviction for second-degree kidnapping in Multnomah County in 1985, in line with the Oregon Division of Corrections.

Mr. Plympton was 16 when Ms. Tucker was murdered. Witnesses reported seeing her with a person the evening she was killed, and several other folks reported seeing her run into the road waving her arms, maybe making an attempt to flag somebody down for assist, The Oregonian reported.

Kirsten Snowden, the Multnomah County chief deputy district legal professional, stated on the trial that there was no proof that Ms. Tucker and Mr. Plympton had identified one another, in line with The Oregonian.

Mr. Plympton’s lawyer, Stephen Houze, stated on the trial that there was “unmistakable, unavoidable reasonable doubt” about who killed Ms. Tucker, in line with The Oregonian. He stated that witnesses had described the person who was seen with Ms. Tucker — who was practically six ft tall — as being about her peak or taller, however Mr. Plympton was nearer to 5-foot-8. He additionally stated investigators by no means examined Ms. Tucker’s clothes for DNA proof.

“We will appeal, and we are confident that his convictions will be overturned,” Mr. Houze and his legislation companion Jacob Houze stated in an announcement on Tuesday.

Decide Amy Baggio of Multnomah County Circuit Court docket discovered Mr. Plympton responsible of 1 depend of first-degree homicide, and 4 counts of “different theories of murder in the second degree,” in line with the district legal professional’s workplace.

“To be clear, this court has zero doubt whatsoever that Robert Plympton beat Barbara Tucker in her head and face until she died,” she stated on the trial. “He did.”

Decide Baggio didn’t discover Mr. Plympton responsible of sexual assault, saying that prosecutors had did not show past an affordable doubt that he had assaulted Ms. Tucker whereas she was nonetheless alive, The Oregonian reported.

Mr. Plympton is scheduled to be sentenced on June 21. Based mostly on his age on the time of Ms. Tucker’s dying, he faces a life sentence with the opportunity of parole after 30 years on the first-degree homicide cost.

Two members of Ms. Tucker’s household wept and embraced after the decision was introduced, in line with The Oregonian. Ms. Tucker’s older sister, Alice Juan, stated in an announcement on Tuesday that her household was “thrilled that this was finally solved.”

“I thought it might not be as the years went on, but Barbie was a special little girl,” she stated. Her little sister, she added, “was bright, bubbly, caring, all of those things.”

Kitty Bennett contributed analysis.