The warnings began a few weeks before 6-year-old Donmiguel Nathaniel Wilson Jr. was killed. His mother, Julia Barber, had started talking to herself, and her family was worried.

So Donmiguel was taken in by his great-grandfather and his younger brother by his grandmother. The idea, Juanita Barber said, was to ease the stress that seemed to be enveloping her 27-year-old daughter.

But cutting off her daughter from her children entirely was not an option. Last month, when Barber asked to have her boys for the weekend, Juanita Barber agreed, according to court documents filed yesterday.

It was the last time Juanita Barber saw her grandson Donmiguel alive.

He was found two days later, July 18, lying face down in a bathtub in his mother's apartment on Wheeler Road SE. His grandmother and her two younger daughters had shown up that morning looking for Julia Barber. The boy's hands were tied behind his back and duct tape residue was around his mouth.

In describing the events that led to Donmiguel's death, prosecutors and police depict a woman who appeared, to those closest to her, to be dangerously troubled in the days before her son was killed.

Leaving the courthouse yesterday, Barber's grandfather, accompanied by other relatives, said he had nothing to say about the case against his granddaughter.

On the morning Donmiguel's body was discovered, Julia Barber was nowhere to be found. After surfacing later that day, she quickly became the suspect in her son's death. Initially, she tried to cast suspicion on an ex-boyfriend, but she eventually admitted that she had killed Donmiguel, "who had been bad all day," according to the affidavit.

Barber was taken for an emergency evaluation after her behavior became erratic, and psychiatrists subsequently found her to be mentally ill and a danger to herself or others. She was taken to St. Elizabeths Hospital, the District's mental health hospital, where she has remained.

On Saturday, nearly a month after Donmiguel's death, Barber was arrested and charged with murder. Her mental health is likely to be a central issue in the case, and the sparring began yesterday as Barber appeared in court for the first time on the murder charge. Dressed in blue jeans and a red-striped shirt, she stood quietly beside her attorney, Santha Sonenberg of the D.C. Public Defender Service.

Arguing that Barber's commitment to St. Elizabeths raised questions that needed to be answered, the prosecutor, Assistant U.S. Attorney Deborah Sines, asked the court to order a preliminary competency screening to determine whether Barber is fit to stand trial.

Sonenberg objected, saying that Barber has been a willing and able participant in her own case since being admitted to St. Elizabeths and did not need such a screening. "She understands what's going on," Sonenberg told the court.

But Magistrate Judge J. Dennis Doyle sided with the prosecutor and ordered the screening, with the finding due back to the court by Thursday.

Barber had been in a secure civil wing of the hospital but will be transferred to the hospital's John Howard Pavilion, where examinations are conducted in criminal cases.

Since Barber was hospitalized, information about her current mental condition and about her mental history have emerged from court documents filed as part of the civil commitment process. The documents suggest that her mental problems date back more than a decade and include an attempted suicide.

The belief that a murder suspect is mentally ill is not sufficient to establish a legal connection between an illness and a crime. Prosecutors generally will charge a person to initiate a full-scale examination, starting with the question of the person's competency. If the person is found to be mentally ill but competent to stand trial, the next consideration could be whether, because of the mental illness, the person understood the wrongfulness of his or her conduct.

Julia Barber, shown in 2000, is charged with murder.