A Kansas woman whose 3-year-old son suffered severe abuse before he was killed and his body encased in concrete was sentenced Thursday to 25 years in prison after she acknowledged that she failed as a mother.

During the hearing, Miranda Miller and her attorney, Steven Wagle, asked Sedgwick County District Judge Stephen Ternes for a lighter sentence, saying her live-in boyfriend, Stephen Bodine, controlled her through physical violence, mental abuse and drugs, The Wichita Eagle reported .

Investigators say Bodine killed Evan Brewer in May 2017 and hid his body. Before that, prosecutors say, Evans was subjected to months of abuse at the hands of Bodine and Miller — including standing naked and chained for hours and being taunted and slapped while he cried. His body was found in concrete after the couple moved out of their rental home in Wichita.

Miller pleaded guilty in late 2018 to second-degree murder, aggravated kidnapping, child abuse and aggravated endangering a child. As part of her plea deal, she testified against Bodine, who was convicted of first-degree murder, child abuse and other charges and is serving a sentence of 109 years and six months in prison.

Miller acknowledged Thursday that she should have called police when the abuse first started.

"At the time, I did what I thought was best," Miller said. "In the end, I failed as a mother to protect my child. I will live with that the rest of my life."

But the judge and Evan's relatives didn't accept her explanation that Bodine was controlling her.

"While I did hear your statements, I must say after hearing the evidence in the trial that you are more than a mother who failed to protect her child. You actively participated in his murder," Ternes said.

During Bodine's trial, prosecutors called dozens of witnesses and presented more than 550 pieces of evidence, including parts of the concrete tomb, videos and photos showing Evan being abused.

Among those who spoke Thursday was Evan's father, Carlo Brewer, who was kept from his son by Bodine and Miller in the weeks before the boy's death.

"The day Evan was found, I was in disbelief and denial. I thought there was no possible way that anyone, even the worst individuals, could look into his beautiful, innocent eyes and harm him. I didn't believe that a mother was harming or allowing someone to harm their child," Carlo said. "The individual who gave birth to this child betrayed him, and was his predator."