DENVER (AP) - A man charged with murder in the death of his missing fiancee tried to convince a woman he was having an affair with to commit the killing, investigators testified Tuesday.

Patrick Frazee was in a Colorado court for a hearing to determine whether he will stand trial in Kelsey Berreth's death. Testimony revealed that police initially found no evidence of foul play inside Berreth's home but later discovered traces of blood belonging to the 29-year-old flight instructor in several places in her bathroom.

The woman has not been found since she disappeared on Thanksgiving Day, Nov. 22.

Authorities had released little information about what led to Frazee's arrest a month later until Tuesday's hearing, which requires prosecutors to convince a judge that their evidence merits a criminal trial.

Testimony on Tuesday still did not reveal prosecutors' theory for a motive why Frazee would kill Berreth or how she died.

Her parents argue in a wrongful death lawsuit filed last week that they believe Frazee wanted full custody of the couple's 1-year-old daughter. The child has remained with them while the criminal case against Frazee proceeds.

The case relies heavily on the cooperation of Krystal Jean Lee Kenney, a 32-year-old woman from Idaho, who has pleaded guilty to helping thwart the investigation by tampering with evidence in the case. She has agreed to testify against Frazee.

Dramatic testimony on Tuesday revealed that Kenney admitted beginning a romantic relationship with Frazee in March 2018. Bureau of Investigation Agent Gregg Slater testified that Kenney told police Frazee claimed that Berreth was abusing the couple's daughter, although Slater said there was no evidence that was true.

Kenney said Frazee suggested multiple ways that she could kill Berreth, including poisoning her coffee or striking her in the head with a metal rod and a baseball bat, Slater said.

Kenney told police she wanted to please Frazee and feared that he would harm her or her family if she did not cooperate. Kenney told police she did not follow through on any of Frazee's plans, Slater said.

Berreth's body has not been found. Investigators initially said she was last seen on surveillance video with the couple's daughter at a grocery store near her home in Woodland Park, a mountain town near Colorado Springs, south of Denver.

Police later found footage on a neighbor's surveillance camera showing Berreth, Frazee and their daughter at the entrance of Berreth's townhome later that afternoon.

Much of prosecutors' evidence hinges on cellphone tower data, suggesting Berreth's phone was in the possession of either Frazee or Kenney after Nov. 22, the date Frazee told police he last saw Berreth.

Frazee, 32, has not entered a plea and has been jailed since his arrest. Prosecutors this week added a charge accusing Frazee of tampering with a deceased body and two charges of committing a crime of violence, which would let the state request a harsher penalty on conviction.

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