Patrick Parnel originally had been charged with second-degree murder.
KXRO reports the charge was amended Tuesday and the 21-year-old was rebooked into the Grays Harbor County Jail with bail doubling from $500,000 to $1 million.
Court documents say Parnel and his girlfriend, 21-year-old Brittany Taylor, didn't want anyone to know Brittany was about to deliver, so they went to an Ocean Shores motel on April 3, where she gave birth over the toilet.
Taylor told detectives she thought the baby was dead at birth and told Parnel to "take care of it" while she remained at the motel. Parnel took the baby to a wooded area a few miles away and covered it in leaves, court documents revealed.
When the baby, who was still alive, began crying, Parnel went back to the car and got an object to beat the infant, according to court documents. The coroner ruled the baby died from blunt force trauma to the head.
Brittany Taylor is charged with abandonment of a dependent person.
The day after the baby's death, the couple went for a walk on the beach and smoked marijuana before going to Taylor's mother's house, court records show.
The couple stayed another night at the motel. They checked out on Friday morning, went to a liquor store and then went home.