A former Idaho nurse was sentenced to three years in prison on Tuesday for helping Patrick Frazee cover up the murder of his fiancée last Thanksgiving.

Krystal Lee, 33, was sentenced after pleading guilty in February to evidence tampering and testifying against Frazee, her on-again, off-again boyfriend, who was convicted of killing 29-year-old Kelsey Berreth.

“I know that saying sorry is not good enough,” she told a packed Teller County courtroom on Tuesday, before receiving the maximum sentence. “And I don’t even know what the right word would be to describe the remorse that I feel.”

Frazee, a 33-year-old cattle rancher, was convicted in November on all six charges against him for the slaying and disappearance of Berreth and was sentenced to life in prison without the possibility of parole, plus 156 years. Berreth, a flight instructor at Doss Aviation, was last seen at a Safeway grocery store near her Woodland Park, Colorado, home on Nov. 22, 2018.

Prosecutors say later that day, Frazee fatally beat his would-be wife, with whom he shared a child, with a baseball bat before burning her body and the murder weapon at his family’s ranch. The cattle rancher then enlisted the help of Lee, his secret girlfriend, to clean up the crime scene, Lee said.

During her emotional two-day testimony, Lee described her troubled relationship with Frazee—which began as an affair several years ago while she was married and included a secret abortion. While the nurse has denied participating in Berreth’s murder, she later admitted she witnessed him burn the evidence of his crime.

“She shouldn’t have received the plea deal that she did,” Berreth’s parents, Darrell and Cheryl, wrote in a letter read aloud in court Tuesday, according to The Denver Post. “She was an active participant in the murder. The only thing she didn’t do was swing the bat.”

Lee recounted that in 2018, Frazee asked her three times to kill Berreth on his behalf, claiming she was abusing their 1-year-old daughter and needed to be stopped. The nurse said while she initially agreed to help, she backed out before each murder attempt.

“His little girl is being abused,” Lee testified. “I understand if it was wrong. I didn’t know what to do so I didn’t make correct decisions.”

Prosecutors said when Lee failed to help Frazee murder Berreth, the “cold, calculating manipulator” took matters into his own hands. Afterward, Lee said Frazee told her, “I need your help, and I need your help now. You have a mess to clean up.”

Lee said during their frantic clean up of Berreth’s apartment, Frazee told her to “get the candles wiped up, get the bathroom done, and wipe up the footprints,” and threatened to kill her if she failed to do a sufficient job.

“He asked me if I got it done. I told him the best that I could do. He said, ‘You better hope you did, because your life depends on it,’” she said during the trial, according to The Gazette.

After the Nov. 24 cleanup, she said the two went to Frazee’s ranch, where the 33-year-old set Berreth’s body on fire, along with several trash bags.

To further trick authorities, Lee said she took Berreth’s cellphone to Idaho—nearly 800 miles away from the missing mom’s home in Woodland Park—for the signal to ping before burning it.