A woman who was having an affair with a Colorado man charged in the beating death of his fiancée said Thursday she helped clean up the bloody aftermath before he burned the body. Meanwhile the defense raised doubts about whether he truly had so much power over her to maintain her silence and cooperation.

Krystal Lee testified for a second day in the trial of Patrick Frazee, who has denied killing Kelsey Berreth at her townhome in Woodland Park, a mountain community of 7,500 people about two hours south of Denver. Frazee would be sentenced to life in prison without parole if he is convicted of first-degree murder.

Kelsey Berreth, Krystal Lee, Patrick Frazee

Berreth was last seen nearly a year ago near her home, and no sign of her body has been found. CBS Denver reported that Frazee's brother, Sean Frazee, testified that the defendant showed up two hours after the family ate Thanksgiving dinner on Nov. 22, 2018 — the last day Berreth was seen alive.

Get Breaking News Delivered to Your Inbox

Lee, who worked as a nurse in Idaho, said she grabbed several blood-spattered items from Berreth's home to be burned, including a stuffed animal, children's building blocks and what she thought was a Bible, according to the Colorado Springs Gazette. She also testified that Frazee and Berreth's baby daughter was in the home when the blindfolded mother was bludgeoned to death with a baseball bat.

Prosecutors showed jurors a video of Lee leading investigators to the spot where Frazee allegedly burned Berreth's body.

Standing in a clear patch of Frazee's central Colorado ranch, surrounded by pine trees, Lee described Frazee putting the body in a dry water trough and lighting it on fire. At one point, she said, flames were as high as the nearby trees, so Frazee covered the blaze with what appeared to be metal roofing.

Lee struck a deal with prosecutors and pleaded guilty in February to evidence tampering, acknowledging she took Berreth's phone to Idaho at Frazee's request to make it look like Berreth had left the state.

Defense attorney Adam Steigerwald seized on that deal and repeatedly asked Lee if she was aware that she could be facing life in prison if she didn't accept it and cooperate with investigators. He also questioned whether she has been fully truthful during her 10 hours of testimony, KOAA-TV reported.

Prosecutors have not offered a motive for Frazee to kill Berreth, but her parents argue in a wrongful death lawsuit that they believe he wanted full custody of the couple's daughter.

There are no cameras allowed in the Colorado courtroom. CBS affiliate KKTV reporter Ashley Franco was in the courtroom as Lee took the stand.

"Krystal Lee says that when she walked into Kelsey Berreth's town home, she saw blood everywhere. … She was cleaning up this massive crime scene," Franco said.