Each person who gave a DNA sample did so on a voluntarily basis, Westminster Police Department spokesman Trevor Materasso said Tuesday afternoon.

Investigators selected people for DNA samples based on a variety of factors, 9Wants to Know learned and Materasso confirmed.

Investigators asked for DNA from the following groups:

  • People who members of the public said should be considered suspects in Ridgeway's killing.
  • People identified through information gathered when police canvassed neighborhoods near her house and where her backpack was discovered.
  • People whose cellphones were used in areas near the crime scene.
  • People who matched the description of a man who tried to grab a woman as she was running around Ketner Lake in Westminster.

Police have said they believe the man who tried to grab the woman near Ketner Lake over Memorial Day weekend is tied to Ridgeway's murder. Police say a jogger was attacked from behind by a man who used a chemical-soaked rag to try and subdue her. The woman fought off her would-be abductor.

The attacker was light-skinned, 18 to 30 years old and had brown hair, according to police.

The DNA samples in the investigation are being taken orally, according to one person who voluntarily gave a DNA sample.

"They swabbed my mouth," said a 26-year-old Westminster resident who said he didn't want his name used.

The man told 9Wants to Know investigator Jace Larson that he had nothing to do with the crime.

"The investigators asked me about my cellphone and wanted to know if anyone else had ever used it. I told them, 'no,'" the man said.

"They told me they wanted my DNA because of where my cellphone was used and because I fit a description."

The man who spoke to 9NEWS said he is 5 feet 8 inches tall with brown hair and fits the age range of the Ketner Lake attacker.

9NEWS confirmed the man who talked to 9Wants to Know does not have an arrest record.

Westminster Police spokesman Trevor Matterasso says the DNA collected on a voluntary basis as part of the Ridgeway case will be destroyed once the case is finished. It will not be entered into a state or federal DNA database, Matterasso says.

He said more DNA could be gathered on a voluntary basis as the investigation unfolds.

"Authorities are casting a wide net using every tool, technology and resource available. With a case this significant, it's likely that forensic analysis may become a pivotal piece in the investigation," he said.

Ridgeway disappeared Oct. 5 as she walked to school in her Westminster neighborhood.

If you have information about her murder, you can contact the Westminster Police Department's tipline: 303-658-4336.