CHICAGO — Bettie Jones, known in her Chicago neighborhood for her work with anti-violence community groups, was killed by police responding to a domestic disturbance just hours after she hosted family on Christmas Day.

The fatal shooting of Jones, 55, and 19-year-old Quintonio LeGrier, a college student visiting his father for the holiday, at a West Side apartment has raised further questions about a police department already under intense scrutiny. Grieving relatives and friends of the two victims gathered Sunday to remember them and criticize city officials who they said had once again failed residents.

The shooting happened early Saturday morning at the small two-story apartment, where Jones lived in a ground-floor apartment and LeGrier’s father in an upstairs unit. Police, who were responding to a 911 call made by LeGrier’s father after an argument with his son, have released few details beyond a brief statement.

It said that officers “were confronted by a combative subject resulting in the discharging of the officer’s weapon” and added that Jones “was accidentally struck.”

Both Jones and LeGrief were black, and their deaths come amid scrutiny of police after a series of deaths of African-Americans at the hands of officers across the country gave rise to the Black Lives Matter movement. It also comes amid a federal civil rights investigation into the Chicago Police Department that was launched after last month’s release of police dashcam video showing white officer Jason Van Dyke shooting black 17-year-old Laquan McDonald 16 times in 2014.

Police did not disclose the race of the officer or officers, saying only that those involved will be placed on administrative duties.

LeGrier’s mother, Janet Cooksey, during a vigil Sunday placed candles on the porch of the home. On either side of the door, Post-It notes indicated where two bullets hit siding on the house.

“I used to watch the news daily and I would grieve for other mothers, other family members, and now today I’m grieving myself,” Cooksey said at a news conference outside the residence earlier Sunday.

Others who spoke said police should have used stun guns or other nonlethal methods if they felt they needed to subdue LeGrier.

“Why do (police) have to shoot first and ask questions later?” Jacqueline Walker, a friend of Jones, asked. “It’s ridiculous.”

Family spokesman Eric Russell said Jones’ many grandchildren had hoped to thank her for their Christmas gifts over the weekend.

Autopsy findings released Sunday by the Cook County medical examiner’s office say Jones died from a gunshot to the chest and LeGrier from multiple gunshot wounds.

Police spokesman Anthony Guglielmi on Sunday said only that the shootings are being investigated by the city’s Independent Police Review Authority, the main police oversight agency.

LeGrier’s cousin, Albert Person, said LeGrier’s father had invited his son to a holiday gathering at another home on Christmas. Person said the son’s refusal to go caused friction, but he downplayed the severity of the argument.

“What family doesn’t fight on the holidays?” he said.