An Arundel man faces a murder charge in the death of his infant son from allegedly grabbing the boy by the head and throwing him into a chair.

Gordon Collins-Faunce is scheduled to appear in York County District Court in Alfred on Friday morning. He is being held on $100,000 bail in the York County Jail, where he was placed on suicide watch, according to county officials.

Collins-Faunce had been charged with elevated aggravated assault on Sunday, but on Tuesday morning, 10-week-old Ethan Henderson died. That made the case a homicide and gave the Office of the Maine Attorney General responsibility for prosecuting it.

On Wednesday, friends and extended family mourned the loss of young Ethan Henderson and struggled to understand how his father could have done it.

A friend Tuesday said Collins-Faunce and his girlfriend, Christina Henderson, Ethan’s mother, previously lived in Farmington.

Collins-Faunce father, Irving Faunce, said he and his wife, Jan Collins, were overwhelmed with grief.

“Jan and I are terribly saddened by the loss of Ethan,” Faunce said. “We are are consumed by grief. Ethan did not deserve to die.”

Faunce, a former Gardiner mayor and Wilton selectman, is a health care consultant who has been outspoken about domestic violence. He has held prominent positions in state government, serving on the Maine Human Rights Commission, Board of Environmental Protection and State Board of Corrections and was an unsuccessful Democratic candidate for the state House of Representatives.

Faunce said he and his wife adopted Collins-Faunce in 1997 after the boy had been in six foster homes over five years. Collins-Faunce, who is now 23, would have been about eight at the time.

Faunce said he was not prepared to talk further.

Police said in court papers that Collins-Faunce had been physically and sexually abused while in foster care, suffered from post traumatic stress disorder and was taking medication for it.

Matt Barley, a friend who knows Collins-Faunce from his time in the Army at Camp Polk at the end of 2010, said he never knew him to be violent.

“He seemed completely normal to me,” Barley said. “The only time it seemed off was when he started talking about fighting someone back in Maine, he got all aggressive when he talked about it. Other than that, nothing really.”

Barley said he did not know why Collins-Faunce left the Army, but suspected it was because he got in trouble.

“It seemed like he actually avoided getting into conflicts with other people, probably because any trouble he got into would just further his time there and he wanted nothing more than to get out of Fort Polk and go home,” Barley said.

On the day of the assault, Henderson had gone to work and Collins-Faunce had stayed home to watch the three children. He returned from having a cigarette outside the mobile home at 521 Limerick Road to find Ethan and his sister crying. That was when he assaulted Ethan, police said.

Deputy Attorney General William Stokes said the charge of depraved indifference murder is appropriate.

“Depraved indifference seemed to be the best fit with the facts right now as we know them based on autopsy results and the evidence we have,” he said.

Unlike other types of murder, depraved indifference murder does not require that the defendant intended to kill the victim, he said.

“Depraved indifference doesn’t require a culpable mental state,” Stokes said. “It looks at the quality of the conduct and whether the risk of death from serious bodily injury of that conduct is so high, it can be described as savage or brutal or outrageous, showing a total lack of regard for the value of human life.”

Collins-Faunce told police that he lost control and grabbed Ethan, squeezed his head and threw him into a chair so hard his head snapped back, according to court papers. Ethan was taken to Maine Medical Center where he eventually died from brain injuries.

Collins-Faunce also told police he brooke Ethan’s arm when the infant was four weeks old. Court papers also say that a day care provider told state workers that another child in the house, Ethan’s three-year-old half sister, Nevaeh, had bruises all over her and that Ethan and his twin, Lucas, were sick and not being given medical attention.

The court papers do not say when the report was made to the Department of Health and Human Services nor whether the reports had been verified. The other children have been placed in state custody.

Stokes would not comment on details of the case including when state protective workers became aware of allegations of abuse n the home and what was done about that.

Stokes said he could not release details, despite the keen public interest, because the murder investigation is just getting under way and premature release of some details could compromise the state’s case.

The case is likely to be presented to a York County grand jury next month.

Collins-Faunce’ lawyer, Amy Fairfield, could not be reached for comment.

Friends created a Facebook page, Remembrance of Ethan Henderson, and planned a candlelight ceremony for this weekend. The event was tentatively scheduled for 7 p.m. Saturday at Deering Oaks in Portland, but that had not been confirmed, according to the page.

A funeral will be held at at Dennett, Craig & Pate Funeral home in Saco, on Saturday at 2 p.m. for family and close friends.