On Nov. 1, Patrick Frazee's murder trial began in Cripple Creek, Colorado. Frazee has been accused of killing Kelsey Berreth, his fiancé and mother of his child, on Thanksgiving Day in 2018. He faces charges of first-degree murder, attempting to commit first-degree murder, and tampering with a deceased human body.

During the first week of the trial, his ex-girlfriend, Krystal Lee, took the stand to recount what had transpired in their relationship. Lee delivered her four-hour testimony on Wednesday, which highlighted what she says truly happened both leading up to and after Berreth's murder.

According to KTVB, Lee testified that she met Frazee in 2006 and the pair dated for about a year before calling it quits. However, she said the pair stayed in touch on and off after they broke up. At one point, Frazee gave her a dog, but he allegedly called her months later and demanded a check for it. "If I didn't send the check, he said he'd come to Idaho and kill the dog," Lee stated.

The two eventually grew apart and lived separate lives, but Lee states that in 2015 they began talking on the phone intermittently around the time she began experiencing trouble in her own marriage. Shortly thereafter, the relationship started up again, but she said at that point she was unaware that Frazee was seeing anyone else or had a daughter.

Lee then said that Frazee told her that Berreth had been abusive to their child. She said he also asked her what combinations of drugs could potentially kill a person due to the fact that Lee worked as a nurse. "He wanted her to not be a problem anymore," she said.

Eventually, Lee met his daughter, which prompted her to begin questioning the abuse allegations as "there were no scars, there were no bruises" on the child. Frazee allegedly requested that Lee kill Berreth in various ways during the course of their relationship, ranging from giving her a cup of coffee with Ambien or Vicodin in it to hitting her with a baseball bat.

After she refused to carry out the plan, Frazee allegedly killed Berreth himself and told her she "had a mess to clean up" on Nov. 22, 2018. Lee revealed that after she helped him do so, the Colorado resident took Berreth's body and belongings to his property, doused them in gasoline, and lit them on fire in a metal trough. She also said she took Berreth's cell phone, purse, and gun before leaving to head back to her home in Idaho.

As for why she did not immediately come forward, she revealed she had been fearful for both her life and her daughter's life, a sentiment that was previously revealed by her friend on an episode of "48 Hours."

During the ongoing trial, it was also revealed that both Frazee and his daughter were seen on video entering Berreth's home, but Berreth was never seen again. He was seen on a neighbor's surveillance camera 11 times throughout the day on Nov. 22, 2018, per CBS Denver.

Additionally, his brother, Sean Frazee, also testified that his brother had shown up late to Thanksgiving dinner last year, which was the last day Berreth was seen alive.

Frazee's murder trial is set to last for approximately three weeks and is scheduled to end on Nov. 22.

crime scene
This is a representational image showing a crime scene tape in Sunset Valley, Texas, on March 20, 2018. Getty Images/Scott Olson