This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

CRIPPLE CREEK, Colo. — Prosecutors will be permitted to conduct DNA testing on a tooth fragment found on the ranch of a Colorado man suspected of killing the mother of his child and burning her body, a judge ruled Friday.

The Gazette reports that investigators discovered the fragment while searching a ranch owned by Patrick Frazee, who has pleaded not guilty to killing Kelsey Berreth.

District Judge Scott Sells ruled that the Colorado Bureau of Investigation may proceed with the testing in the presence of attorneys for Frazee.

Berreth, a 29-year-old flight instructor, was last seen on Nov. 22, 2018, at a supermarket near her home in the mountain community of Woodland Park. The search for her started on Dec. 2, when her mother reported her missing. Her body has not been found.

Berreth and Frazee were engaged, but lived in separate homes.

Krystal Jean Lee Kenney, a former Idaho nurse, told authorities that she and Frazee had been dating and that he had accused Berreth of abusing their daughter — an allegation authorities have said is not backed up by evidence.

Investigators have testified that Kenney told police Frazee repeatedly asked her to kill Berreth but that he later admitted to beating Berreth to death with a baseball bat. She said Frazee demanded she clean up blood at Berreth’s home and watched as Frazee burned Berreth’s body, according to investigators.

Kenney told police that Frazee planned to dispose of Berreth’s remains in a dump or a river, investigators have said.

District Attorney Dan May said Friday prosecutors have yet to decide whether to pursue the death penalty.

Kenney is cooperating with prosecutors as part of a plea agreement in which she pleaded guilty to evidence tampering for moving Berreth’s cellphone after she disappeared.

She faces up to three years in prison but prosecutors have said Kenney will not be sentenced until all trials related to Berreth’s disappearance are completed.

Prosecutors’ evidence includes cellphone tower data, suggesting Berreth’s phone was always in the possession of either Frazee or Kenney after Nov. 22, the date Frazee told police he last saw her.

Prosecutors have not disclosed theories on why Frazee would kill Berreth.

Her parents argue in a wrongful death lawsuit that they believe Frazee wanted full custody of the couple’s toddler daughter. The child has remained with them temporarily while the criminal case proceeds.

Frazee’s criminal trial is set for Oct. 28.