The incident took place in 1994, and the victim, who was 67 at the time of the attack, died in 2000.
But Shores will belatedly pay for the crime.
A jury has now convicted him following an investigation executed by the cold-case-project unit of the Denver District Attorney's Office.
Warning: The details of the case, detailed in an arrest report on view below, may disturb some readers.
At about 5:35 a.m. on September 6, 1994, as we've reported, officers were called to the 2000 block of Colorado Boulevard.
Not far from this location, they found the 67-year-old female assault victim. She was lying in a grassy area being assisted by two elderly men and the clothes she was wearing were "torn and misplaced," the document states.
The victim, who'd walked away from an unnamed "personal care boarding house" a couple of days earlier, was given a sex-assault exam at University Hospital in addition to treatment for "closed fractures of facial bones, abrasions and friction burns." She didn't have any teeth, either, but investigators subsequently learned that was normal for her.
Efforts to interview the woman about the person who hurt her so badly went for naught. The police report blots out her diagnosis, but it notes that she was transferred to the facility's psychiatric wing. She was subsequently placed in a Grand Junction-area nursing home and passed away in December 2000 from colon cancer unrelated to the attack on her.
Over the intervening years, no arrest was made for the woman's attacker. But this past January, a break came after a forensic scientist with the Denver Police Crime Lab ran a sample from the woman's rape kit through a national DNA database and scored a hit with Donald Shores, described as "an over-the-road truck driver for a Michigan-based transport company."
Shores had been busted in Texas for conspiracy to distribute meth — and he was also a suspect in an alleged sex assault on another disabled victim in Temple, the Texas community where he'd most recently been living.
The woman in question was only 48, but she more than fit the qualifications for being "at risk."
A staffer at the facility that cared for her told a Denver investigator that she "mumbled a lot and was hard to understand because she had no teeth."
Her mental health was problematic as well. The facility employee said she "couldn't be trusted to go across the street to the grocery store without getting lost" and actively avoided bathing. He believed "any normal person" would know immediately that she suffered from impairment.
The Texas arrest report in the case said Shores met the woman in a hospital emergency room and was visiting her residence a few days later when he fell asleep in her bed. After discovering Shores there, the woman took some medication that "knocks her out" and laid down in the bed alongside him.
Those who want to know the horrifying details about what allegedly happened next can read about it in the police report — but evidence included bloody sheets and a bloody adult diaper.
The extradition of Shores to Colorado was put in motion last summer, and yesterday, a Denver jury found him guilty of first-degree sexual assault. He's scheduled to be sentenced on May 28.
Look below to see another Shores mug shot, followed by the police report.
Send your story tips to the author, Michael Roberts.