ROSEBURG, Ore. -- Mark Vanderhoof, 50, of Roseburg, was officially arraigned on Friday for the murder of his girlfriend's two year old son.
A search of court documents has shown that he was convicted of raping a 4-year-old girl back in 1988. He served 10 years of a 20-year sentence before being released from the Oregon State Penitentiary. The documents say he had three prior convictions, all involving assaulting behavior.
Vanderhoof appeared by video arraignment Friday in a Douglas County courtroom, and the District Attorney's office amended the original charge of assault to murder, after the death of Young.
The boy, Dennis James Young, had been hospitalized since Tuesday, first at Mercy Medical Center in Roseburg before being taken to Oregon Health & Science University hospital in Portland.
The boy died at the Portland hospital just after midnight Friday morning.
Detectives met with and interviewed the boy's mother and Vanderhoof in Portland. The Douglas County Sheriff's Office took Vanderhoof into custody Wednesday on a charge of first degree assault.
Doctors reported the boy's injury was life-threatening and inconsistent with the explanation reported by Vanderhoof and his girlfriend, the boy's mother, Briana Lyn Snow, 31.
According to the affidavit for probable cause, Portland police and Douglas County Sheriff's deputies talked with Vanderhoof at the hospital and he, "admitted to striking Denis Young with sufficient force to cause the injuries to the child.
Snow was away from home Tuesday running errands while Vanderhoof watched the boy, the sheriff's office said. Vanderhoof called her and said she needed to come home right away because the boy had fallen off the front porch and hurt himself.
When she got home, she found her son unconscious and seriously injured. She called 911 for an ambulance.
Vanderhoof will have an attorney appointed for him, but no date has been set for the next hearing.
He faces possible life in prison if convicted on the murder charge.