(AP) — A man who was under a restraining order and not supposed to have a gun fatally shot his three daughters, a chaperone and himself during a supervised visit with the girls at a California church, officials said Tuesday.

Investigators were trying to piece together the father’s motive and how he got the weapon used in the shooting that occurred at about 5 p.m. Monday. Under California state law, he was not supposed to have a gun because of the restraining order.

On Tuesday morning, a small memorial with flowers, balloons, stuffed animals, a candle and a piece of paper that read “Prayers for peace, may your souls rest” was set up outside the church in the Arden-Arcade neighborhood of Sacramento.

The girls — ages 9, 10 and 13 — attended schools in the Natomas Unified School District in northwestern Sacramento. Counselors and chaplains were at the schools Tuesday to provide support.

“There are very few words that can give comfort right now for this unspeakable tragedy,” the school district said in a statement.

Yadira Ortega lives across the street from the church and said she heard the gunfire while sitting in her car after returning home from picking up takeout dinner for her family. She was with her 9-year-old daughter and 6-year-old son.

Ortega said there were multiple shots, then a pause before a final shot. Minutes later the area was swarming with police, she said.

Ortega said she knew little about the non-demoninational church named The Church in Sacramento said it’s busy on Sundays but mostly quiet during the week.

The Sacramento County Sheriff’s Office has offered few details about the shooting inside the church, which sits on a mostly residential block near a commercial area east of downtown Sacramento. Authorities have not disclosed the names of the 39-year-old gunman or the victims and have not said what type of weapon used.

Sacramento County Sheriff Scott Jones said the shooter was estranged from his daughters’ mother, who had a restraining order against him. Detectives are treating the shooting as a domestic violence incident.

Investigators believe the shooting happened during a supervised visit for the father inside the church with the children and a chaperone who also was killed.

Joyce Bilyeu, deputy director of the Sacramento Regional Family Justice Center, said the specifics of supervised visitations can vary widely.

Sometimes, a victim will request that a pastor or grandparent be the chaperone in their home or church, she said. Other victims seek professional supervision with a trained mediator in a safe location close to law enforcement, but that option can be costly, Bilyeu said.

Bilyeu said visits in places like churches can give victims a false sense of security.

“Generally a lot of people think a church is a safe place,” she said. But “there’s no metal detectors in a church.”

A restraining order, while a typical part of the process in domestic violence cases, should not be considered a solution or deterrent to abuse, she said.

“It is not a shield of armor,” Bilyeu said.

A man who emerged Tuesday from the church several times to talk to reporters outside said the church is made up of multiple buildings, including a living space where he and several other members live.

The man, who only gave his name as Alfredo, said he was in the church’s main building when the shooting happened and that neighbors called police because he did not have a phone.

He declined to provide more details, saying church elders planned to issue a statement later.

Officials did not know if the victims attended the church. No events for Monday were listed on the church’s online calendar.

After the shooting, California Gov. Gavin Newsom tweeted: “Another senseless act of gun violence in America — this time in our backyard. In a church with kids inside. Absolutely devastating.”

Newsom last month proposed letting private citizens in California sue gun makers to stop them from selling assault weapons.