SHELBY COUNTY, Ind. -  

A man pleaded guilty to a felony charge related to the death of his girlfriend's toddler last year.

Nathan Barker, 31, is accused of fatally injuring 22-month-old Jasper Simpson, the son of Barker's then-girlfriend, Amanda Simpson.

The baby was flown to Riley Hospital for Children on Aug. 1, 2011, where he died, after his mother had found him not breathing.

Barker told police that Jasper had fallen off the couch, but neighbors reported that they had seen Barker abuse the toddler, according to court documents.

According to the Marion County Coroner, the toddler had several injuries all over his body, including to his cheek, neck, shoulder, genitalia and rectum. He also had internal injuries.

The coroner determined the cause of death was blunt force trauma and ruled the death a homicide.

Barker's sentencing is scheduled for Nov. 29, and his sentence will be determined by a judge. Barker could serve up to 40 years for neglect of a dependent causing death.

As part of a plea agreement, Barker's two other charges -- battery resulting in death of a victim under 14 and neglect of a dependent -- were dropped.

Barker has been in custody since three weeks after the toddler's death.