A mother whose three children were shot and killed this week inside a Sacramento County church during a supervised visit with their father obtained a restraining order against him last year after telling court officials that he was violent and had threatened to kill her.The father, David Mora, 39, shot and killed his three daughters — ages 9, 10 and 13 — and a church official who had agreed to supervise the visits, before fatally shooting himself, according to law enforcement officials, the coroner’s office and court records.The shooting on Monday came after Mr. Mora’s partner of 15 years described his history of violence in court documents filed in late April 2021. The New York Times is withholding the name of the woman. A telephone call to her was not returned on Wednesday.The order, granted in May 2021, outlined terms allowing for Mr. Mora to visit with his children, and it prohibited him from purchasing or possessing firearms.Mr. Mora “said that he has not killed me because he would not know where to go with the children,” the woman said in court documents. She added: “I am scared and nervous. I am afraid Respondent is going to hurt me.”The woman also said Mr. Mora had physically abused her in the presence of their three children.She said the most recent abuse took place in their home on April 17, 2021. The couple got into an argument when the woman said she wanted to leave her job selling tamales and start cleaning homes. Mr. Mora, she said, did not want her to do that. “He threw a ball at me,” she wrote. “He grabbed my right arm and pushed me” and “he was acting crazy.”The woman said she called a friend from church to pick her up. The next day, she called the police. Mr. Mora, she wrote, “had been expressing a desire to kill himself,” and he was “admitted into the hospital for a week and treated for psychosis.”The woman said she and the children moved out of the home they shared with Mr. Mora. The children had witnessed his behavior, she said. “They were scared and crying. My oldest child was biting her nails off.”Earlier that same month, Mr. Mora kicked the woman so hard that her left leg was bruised, after she said she did not have to have sex with him, according to court documents.And in February 2020, the woman wrote that Mr. Mora threatened to kill her if he ever caught her cheating. She also said that Mr. Mora “is a very jealous person” who “has choked me in the past.”The woman said Mr. Mora had not threatened her with a weapon and was not in possession of any. It is unclear how he obtained the weapon he used on Monday. The Sacramento County Sheriff’s Office did not immediately respond to an email requesting comment on Wednesday.Restraining orders have become important tools for victims of domestic violence to ensure their safety, though the ability to enforce them has sometimes been challenging. Researchers at the University of Pennsylvania and the Fielding School of Public Health at the University of California, Los Angeles, found that in a study of 231 women who had been killed by their male partners, 11 percent had been issued restraining orders. Of those, about one-third of the women were killed within a month of obtaining restraining orders.On May 19, 2021, the Superior Court of California in Sacramento granted the woman a five-year restraining order. In it, the couple agreed to let Mr. Mora visit the couple’s children for “up to four hours per visit, supervised” by a man identified by church records and the coroner’s office as Nathaniel Kong. (Court records spell the man’s last name as “Alcon.”) A man who answered the phone listed for Mr. Kong’s wife said on Wednesday that she was not available to speak.In seeking a restraining order, the woman said she was concerned about Mr. Mora’s “mental stability” and wanted his visits with the children to “be supervised by my friend.”If Mr. Kong was not available, the couple agreed to have an agency supervise the visits at Mr. Mora’s expense, according to the restraining order.Such costs can be expensive. Professional supervised-visitation monitors can range from $40 to $100 an hour, according to Dr. April Hayes, the executive director at the Sacramento Counseling and Family Service Center, which provides monitoring and counseling.A federal grant to help low-income parents pay some costs of those visits is no longer available in Sacramento, according to Dr. Hayes, who has worked in the field for about two decades.Parents who cannot afford the cost of professional monitors often make arrangements with well-meaning but not professionally trained monitors, and can arrange meetings at churches or restaurants where security precautions are harder to ensure, she said.In 2012, Dr. Hayes said she was assaulted by a parent whose visit she was monitoring inside a church.Referring to supervised meetings at her agency, Dr. Hayes said, “We have a lockdown process.” To ensure safety, people at the agency have at times used wands to check parents, she said. Though effective, such security measures are not always appreciated by parents in what can already feel like a contentious setting, Dr. Hayes said. “Parents being supervised feel victimized.”“I really wish there was a better system,” she said, “but I don’t know what the answer is.”