OKLAHOMA CITY - The father who beat his little girl to death in June 2011 pleaded guilty Friday, December 2, to first-degree murder.

A judge in Oklahoma County sentenced Sean Brooks to life in prison for killing his 5-year-old daughter, Serenity Deal. He will have to serve at least 38 years in prison before being eligible for parole.

Prosecutors say Brooks called police June 4. When officers arrived at Brooks' apartment, they found Serenity unconscious with signs of child abuse to her body. Brooks originally told police the little girl had fallen in the shower, but an investigation revealed Serenity was beaten to death.

Serenity's death led to an investigation within DHS into why Brooks was allowed to have custody of his daughter even though there had been previous reports of child abuse against him.