A former Mississippi police officer on Tuesday was given the maximum jail sentence of 20 years for the death of her 3-year-old daughter. 

Cassie Barker, 29, admitted in March to leaving her daughter, Cheyenne Hyer, strapped in the backseat of her hot patrol car for four hours in September 2016 while she had sex with a supervisor following one of her shifts. The child was found unresponsive in the patrol car and later pronounced dead at a hospital after a body temperature of 107 degrees.

Barker had pleaded guilty to culpable negligence manslaughter.

"I don't know what I could ever do to you that could be worse than what you've already experienced ... You will forever be entombed in a prison of your own mind," the judge told Barker in March.

Barker reportedly had previously left Cheyenne Hyer unsupervised in a car, which led to welfare officials taking custody of the child.

Ryan Hyer, the father of the Cheyenne Hyer, wanted Barker to receive the maximum sentence.

"You lose your child, I don’t think there’s no amount of sentencing or time that could make up for that," Hyer told WLOX, an ABC/CBS affiliate in Biloxi. "But this is how the justice system works. With what the judge had to work with, I’m happy that he gave her the max that was allowed by law."