After over forty years of uncertainty, a discarded piece of chewing gum has emerged as the crucial evidence leading to the resolution of a cold-case murder that had puzzled authorities in Oregon since 1980.
Robert Arthur Plympton, aged 60, was found guilty on Friday of the murder of Barbara Mae Tucker, a college student at Mount Hood Community College, after a three-week bench trial in Portland, Oregon. The trial marked the conclusion of the oldest cold-case homicide investigation in Gresham, Oregon, east of Portland.
The case dates back to January 15, 1980, when Ms. Tucker, a 19-year-old student studying business, vanished on her way to class. Her partially clad body was discovered the following morning on a shrub-covered slope near a campus parking lot, showing signs of sexual assault and struggle with her assailant.
Decades passed without a breakthrough until 2000 when vaginal swabs from Ms. Tucker's autopsy were analyzed, leading to the development of a DNA profile. In 2021, Parabon NanoLabs identified Mr. Plympton as a probable contributor to the DNA profile.
Gresham Police detectives began surveilling Plympton, and upon witnessing him discard chewing gum, collected it for DNA analysis. The DNA profile from the gum matched that of the swabs taken from Ms. Tucker's body.
Plympton, who had a prior criminal record, including a conviction for second-degree kidnapping, was arrested on June 8, 2021.
During the trial, Kirsten Snowden, the Multnomah County chief deputy district attorney, asserted that there was no evidence of a prior connection between Plympton and Ms. Tucker. Plympton's defense argued there was reasonable doubt, citing discrepancies in witness descriptions and untested DNA evidence from Ms. Tucker's clothing.
Ultimately, Judge Amy Baggio of Multnomah County Circuit Court found Plympton guilty of first-degree murder and four counts of second-degree murder. However, he was not convicted of sexual assault due to insufficient evidence.
Plympton faces a life sentence with the possibility of parole after 30 years. The sentencing is scheduled for June 21.
Following the verdict, members of Ms. Tucker's family expressed relief and closure, with her sister, Alice Juan, stating that they were "thrilled that this was finally solved" and recalling Ms. Tucker's vibrant personality and caring nature.
