Roy Rankin was convicted of wanton murder and first-degree criminal abuse in the death of Cecilia Alvarado.
A jury recommended he spend 20 years in prison and the judge agreed. But before he was sentenced two decades behind bars, his defense attorneys argued there was no hard evidence he killed his then-girlfriend's baby. The judge agreed with prosecutors,saying a jury had already convicted Rankin.
Rankin's family members were outraged and say they'll appeal the case.
Alvarado's mother, Samantha Monahan, was found guilty of abuse in the case. She'll be sentenced next week.