A D.C. man was sentenced to 50 years in prison for killing a 21-month-old boy.

Prosecutors said 35-year-old Jonathan M. Austin was babysitting for his girlfriend’s son, Ronjai Butler, in November 2008. When the girlfriend returned to the apartment, Ronjai was semi-conscious and Austin claimed nothing had happened.

Ronjai was taken to Howard University Hospital in cardiopulmonary arrest and died at the hospital. Prosecutors and court records say the boy had suffered a skull fracture, multiple rib fractures, lacerations to the lungs, liver, spleen and kidneys, and several bruises.

Austin was convicted of first-degree felony murder and first-degree child cruelty in a November 2010 jury trial in D.C. Superior Court.