See the startling video that helped convict Kelsey Berreth's killer

New video shows Patrick Frazee's secret girlfriend Krystal Lee at the murder scene showing investigators how she cleaned up after the bloody crime

Girlfriend of convicted killer walks cops through crime scene
Girlfriend of convicted killer walks cops thr... 00:45

Last Updated Jul 30, 2020 11:44 AM EDT

"48 Hours" and CBS News correspondent Nikki Battiste have an inside look at the startling evidence that helped convict Colorado man Patrick Frazee for the murder of his fianceé in an encore of "Justice for Kelsey Berreth" airing Saturday, August 1 at 10/9c on CBS.

A national spotlight was trained on a small courthouse in Colorado this week as Patrick Frazee was found guilty of killing his fiancée, Kelsey Berreth, last Thanksgiving. The case had a star witness, Frazee's secret girlfriend, Krystal Lee.

In new evidence that was just released, Lee is seen on video for the first time taking investigators through the crime scenes.

Lee had been at home in Idaho last year when Frazee called to summon her to Woodland Park, Colorado, because she had "a mess to clean up." Lee, who says she was both in love with and fearful of Frazee, drove nearly 12 hours, picking up the keys to Berreth's home from Frazee and performing a massive clean-up of blood and evidence there.

On the very day Frazee was arrested last December, Lee can be seen wearing a Colorado Bureau of Investigation jacket and hat, taking police through Berreth's home. She points out the many places that had blood spatter when she first arrived to clean, all the result of Frazee beating Berreth to death with a baseball bat. She says she cleaned the place from top to bottom and removed evidence. But she also claims to have left traces of blood behind in the hope that police would find them and connect Frazee to Berreth's death.

Lee told police that after Frazee killed Berreth, he removed her body to his ranch where he burned her remains and other evidence in a big bonfire on his property. In the video, Lee is seen taking investigators there as well, showing them exactly where the fire was and telling them everything that burned, down to the clothes she had worn for the cleanup.

In return for her cooperation and testimony, Lee entered into a plea deal and will serve up to three years for evidence tampering.