Investigator's dumpster dive for DNA nets conviction in 40-year-old murder case

On Thursday, an Arapahoe County jury found David Dwayne Anderson guilty of murdering a Cherry Hills woman inside her home four decades ago.

The case was built on a new DNA sample obtained by an investigator who collected trash bags from an apartment complex dumpster last year. 

Anderson resided at the complex. Lab results found Anderson's DNA on a soda can. 

The soda can DNA matched that found at the crime scene. 

"For more than 40 years, the Defendant carried with him a dark secret, a secret that was finally revealed during this trial," stated Deputy District Attorney Grant Grosgebauer, one of the prosecutors on the case, in a press release from the 18th Judicial District Attorney's Office.

Sylvia Quayle, 23, was found dead inside her home in the 3800 block of South Ogden Street on Aug. 4, 1981. She had been stabbed several times, shot once in the back of the head, and sexually assaulted. 

Her father made the discovery.

DNA collected from the scene went unmatched for years, even after the Colorado Bureau of Investigation sent the samples to the Federal Bureau of Investigation in 2000. 

In 2020, detectives from the Cherry Hills Police Department began working with a genetic genealogy company, United Data Connect, according to the DA's Office press release. That company's work narrowed the case's leads. 

It was an investigator from the company who discretely acquired Anderson's trash. 

Anderson was arrested in Nebraska and charged with two counts of murder. However, a mistrial was declared in March after jurors were unable to reach a verdict following five days of deliberation. 

Prosecutors brought Anderson before a second jury last month. That jury returned guilty verdicts on both murder counts Thursday.

Anderson is scheduled for sentencing Aug. 4. He could receive life in prison with the possibility of parole after 20 years, according to the DA's Office.

"When we first started our Cold Case Unit in 2013, this is a case most people said would never be solved. But time and science march on, leading us to justice today," District Attorney John Kellner said. "This verdict should give hope to all those who are still waiting for justice and for any killer who thinks they got away, know that we are still coming for you."