AUGUSTA — A Wayne man has been arrested after allegedly throwing his 3-month-old son down a flight of stairs.

William Lord Jr., 39, of 57 Innes Road is charged with aggravated assault, domestic violence assault on a child less than 6 years old and domestic violence terrorizing, according to records in Kennebec County Superior Court.

He is being held in lieu of $5,000 cash bail or $50,000 worth of real estate following a court hearing Monday afternoon.

The boy’s mother, Ericka Melanson, took the baby early Monday to MaineGeneral Medical Center in Augusta, where he is being treated for a skull fracture, said Stephen McCausland, spokesman for the Maine Department of Public Safety. The injury is not believed to be life-threatening.

Conditions of bail prohibit Lord from contact with his son and the boy’s mother.

Lord, who police say was intoxicated, allegedly threw his son Preston down a flight of stairs while the baby was in a car seat around 3:30 a.m. Monday, according to dispatch reports.

“The baby was not secured in the seat and struck his head,” McCausland said.

An affidavit by Maine State Police Trooper Dane Wing filed in court said Preston “got ejected from the seat and landed face first.”

Melanson said the baby was not breathing at first, but began once she picked him up, according to Wing.

The mother told police that she heard Lord say Preston deserved to be thrown down the stairs.

Melanson, 21, also told police that Lord had recently been fired and was becoming increasingly difficult. She told police she felt she had to leave the residence or he would have shot her.

“Ericka advised that on several different occasions, William has made comments that if she brings police to the residence again, he will shoot the police and will feel bad for their families,” Wing wrote.

Another child lives in the house but was not injured, McCausland said.

Lord went to bed after Melanson took the infant to the hospital, McCausland said.

McCausland said police were notified after Melanson took Preston to the hospital. He didn’t elaborate on who called the police or when it happened.

A state police tactical team went to the house after securing an arrest warrant. Lord was arrested around 7 a.m. Monday after an older child left for school on a bus.

“(Lord) was awakened this morning by a PA system from the tactical team,” McCausland said. “Lord came outside the house and was taken into custody.”

The court complaint listing the charges against Lord also has a Yarmouth address for him.

Kennebec Journal Staff Writer Betty Adams contributed to this report.