Authorities tell Action News they have arrested 27-year-old Joseph Zysk in the crime.
Police believe the child, Jason Larkin , was crying and Zysk beat the boy to death.
Zysk is charged with murder, manslaughter and endangering the welfare of a child.
Medics were called out to the 4200 block of Houghton Street in the Roxborough section at around 3:45 a.m. Saturday.
Police say once inside, they found Larkin's body.
The toddler was taken by ambulance to Children's Hospital where he was pronounced dead a short time later.
Officials say Larkin died from blunt force trauma to the body, adding that the child even had a lacerated liver.
