NORTHGLENN, Colo. -- A Northglenn father was arrested Friday, accused of beating his 4-year-old stepson.

Northglenn police were called to the North Suburban Hospital emergency room Friday at 2:40 p.m.

The staff told police Michael Oschner brought his 4-year-old stepson, Kurt Green, to the emergency room with severe bruising to his head and abdomen. Oschner told the staff the boy had fallen down the stairs while in his care. The hospital said the injuries were not consistent with that type of fall.

Police took Oschner to the Northglenn Police Department for questioning shortly after they arrived. It was there that Oschner changed his tune, police said.

"He ultimately admitted he had struck the 4-year-old with a closed fist out of anger," said Cmdr. Steve Sanders.

Neighbors said the family just recently moved into the neighborhood.   Michelle Vornholt said she is absolutely shocked and horrified by the events.

"I don't see how parents could treat kids that way. It stumps me," said Vornholt.

On Saturday night Oschner remained behind bars at the Adams County Jail. He is booked on felony child abuse resulting in serious bodily injury. His bond has been set at $20,000. The sheriff's department said Oschner will be advised of the charges against him on Dec. 13.

In the meantime, the boy continues to fight for his life. He underwent surgery at Children's Hospital in Aurora Friday and is listed in critical condition in the hospital's intensive care unit.