MOUNT CLEMENS, Mich. -

A man has been sentenced to 270 months in prison after pleading guilty to killing the mother of his son in her Warren home last year.

Shalisa O'Dell, 25, was found beaten to death in the home she was renting on Garrick Street on Dec. 8. 

Read: Police: Woman apparently beaten to death in home

The young mother was discovered by a cousin who went to check on her after O'Dell failed to pick up her 2-year-old son. Police said the child's father, John Carlos Johnson, was questioned in her death and confessed to killing her.

He pleaded guilty to second-degree murder in April.

  At Johnson's sentencing Wednesday, Judge Mary Chrzanowski asked why the beating became a murder.

"He hits her a couple of times and she falls to the floor. Why wasn't that enough?" Chrzanowski asked.

The judge also pointed out Johnson tried to cover up the crime.

"He stated he used towels that were in the deceased's bathroom and then sprinkled powdered cleaner on the couch as well. He's got to clean up because he knows he's committed a crime now," Chrzanowski said.

A tearful Johnson turned to Shalisa's parents and spoke to them in court.

"I'm so sorry that I lied to you," Johnson said.

Shalisa's mother addressed the court, speaking on behalf of her daughter and John's two-year-old son, Josiah.

"I tell her that I'm going to make her be proud of him because I'm going to raise him," Sherri O'Dell said.

Shalisa's father, John O'Dell, said he and his wife are making sure Josiah will remember the mother who was taken away from him.

"Every day when he wakes up, that's the first thing we do before eating breakfast, this is mommy. He sees a picture of her and gives her a kiss," O'Dell said.

John O'Dell said it will be a struggle to forgive the man who murdered his daughter.

"There may be forgiveness but I'll never forget.  You know, it is godly to forgive. It's hell to forget."