ARUNDEL — Maine State Police were monitoring the condition of Ethan Henderson on Monday night to determine whether his father would be charged with assaulting the 2½-month-old boy or killing him.

Police said the baby was in “grave” condition at Maine Medical Center in Portland with severe head injuries, though a hospital spokeswoman declined to give any information about him. Family members found the boy unresponsive Saturday morning and called for help.

Gordon Collins-Faunce, 23, of Arundel was held in the York County Jail in lieu of $100,000 bail. In a video appearance from the jail before a judge in Springvale District Court, he was formally charged with elevated aggravated assault and aggravated assault. He entered no plea.

“If the boy should die, the Attorney General’s Office has already been brought into the loop,” said Steve McCausland, spokesman for the Maine Department of Public Safety. The Attorney General’s Office prosecutes most homicides in Maine.

If Collins-Faunce is released on bail, he will not be allowed to have contact with anyone younger than 18 or with the child’s mother, Christina Henderson, 23.

The couple’s other two children, Ethan’s twin brother and a 3-year-old sibling, have been taken into custody by the state Department of Health and Human Services. The DHHS would not comment on the case Monday, citing confidentiality rules.

A state police affidavit describing the case against Collins-Faunce was sealed by the judge at the request of the prosecution.

Collins-Faunce was arrested Sunday night at his family’s home at 521 Limerick Road. The single-story house was quiet Monday.

Collins-Faunce has no criminal record, according to the State Bureau of Identification. He is employed as a flagger for a road crew, McCausland said.

Staff Writer David Hench can be contacted at 791-6327 or at: [email protected]