A former Mississippi police officer admitted Monday that she was having sex with her supervisor while her daughter was dying in a hot patrol car, local CBS affiliate WLOX reported.

Cassie Barker, 29, pleaded guilty to manslaughter for the death of her 3-year-old daughter, Cheyenne Hyer, Harrison County Circuit Clerk Connie Ladner confirmed to BuzzFeed News.

Barker was initially indicted on second-degree murder charges but reportedly struck a plea deal.

Cheyenne died in 2016 after Barker left her in a patrol car for four hours while she had sex with her supervisor, Clark Ladner, and then fell asleep at his home.

According to the Sun Herald, the temperatures reached over 100 degrees that day. Barker had put on the air conditioner, but it was not blowing cold air.

When she returned to the vehicle, Barker found her daughter unresponsive in her car seat with a body temperature of 107 degrees.

Both she and Ladner were reportedly fired from the Long Beach Police Department as a result.

Ladner has not been charged with any crimes, as he has said he was unaware a child had been left in the car. He could not be immediately reached for comment.

Barker had left her daughter alone in a car the previous April, reportedly while she was at a store. Cheyenne was temporarily placed in custody of child welfare services and Barker was suspended from the police force for a week.

According to Hancock County Sheriff's Office records, Barker was booked into jail Monday night.

Prosecutors have reportedly recommended a sentence of 20 years, but Harrison County Circuit Judge Larry Bourgeois said he wants more time to think about it before her April 1 sentencing.

“I don’t know what I could do to you that could be more than what you have already experienced. You will be forever entombed in a prison of your own mind,” Bourgeois said in court.

Cheyenne's father, Ryan Hyer, is reportedly suing the police department and the Mississippi Department of Child Protection Services for not taking more serious action after the April incident, of which he has said he was not informed.

"As a parent, you are supposed to protect your child, and Cheyenne is gone because her mother didn't protect her, not once but twice," Hyer said in court Monday.

"Every time I close my eyes, I picture her suffering and then I picture her laying in this coffin," Hyer said. "I still see her smiling and laughing in my head and I would assume that smile and laughter turned to pain and suffering in that instance."

BuzzFeed.