The mother of a 6-year-old boy who was found dead in a bathtub with his wrists and ankles bound was undergoing psychiatric tests last night after emerging as a suspect in her child's slaying, D.C. police officials said.

In interviews with detectives Monday and again yesterday, Julia Barber, 27, gave several rambling statements that detectives believe implicate her in the killing of Donmiguel Nathaniel Wilson Jr., police officials said. Police videotaped the interviews, including a conversation between Barber and her mother in which she discussed her son's death, police officials said.

Barber, who also has an 11-month-old son, complained in the interviews about the stress of being a parent and said she had been having problems with Donmiguel because he was not accepting her current boyfriend, police said.

Barber appeared unstable and distraught when questioned, and police had her admitted to an emergency psychiatric program on the grounds of the former D.C. General Hospital in Southeast, officials said.

A warrant charging her with Donmiguel's death was presented to the U.S. attorney's office, but no action will be taken until her psychiatric evaluation is completed later this week, police officials said.

Capt. C.V. Morris of the D.C. police violent crimes branch declined to discuss details of the slaying during a news conference yesterday. However, he told reporters that detectives believe the killing was committed by a family member. He said an arrest was "going to be forthcoming."

"We believe it has to deal with that family," Morris said.

Donmiguel, known as D.J., was scheduled to start second grade at M.C. Terrell Elementary School in September. His body, bound with cloth at the wrist and ankles and lying in a foot and a half of water, was discovered Monday morning by his grandmother when she arrived at the apartment in the 3200 block of Wheeler Road to take him to camp.

The boy's body was covered with a pillow and blanket, police officials said. He had not been gagged, as had been originally reported by police.

An official with the D.C. medical examiner's office said last night that the case had been ruled a homicide and that the cause of death was a combination of drowning, suffocation and head injuries.

In her statements to authorities, Barber said she had left the apartment, which is in the Congress Heights section of Southeast, on Monday morning and got locked out of the building, according to police. She was at a friend's house looking for a key when her mother, Juanita Barber, discovered Donmiguel, police said.

Yesterday, relatives of Donmiguel's father, Donmiguel Sr., 34, were trying to come to grips with the killing and the relationship between the boy and his mother.

Patrick Sweeney, 51, Donmiguel's paternal grandfather, said that other relatives had described Barber as acting strangely in the last week. "She was complaining about voices and talking to the devil," Sweeney said.

Other relatives said that Barber often complained about Donmiguel's behavior, telling them that he tried to start a fire in the apartment, drink bleach and pourjuice into the television. But relatives of the father said they never saw that side of the boy and questioned Barber's accounts.

"She always made it seem like he was the bad child," said April Phillips, a cousin of the boy's. "But when he was over here, he was always the quiet child playing video games."

Wilson and Barber broke up about two years ago, and she began dating another man, who is the father of her 11-month-old son, relatives said. Soon after that relationship started, Barber began preventing Donmiguel's father and other relatives from seeing him, the family members said.

Sheila Phillips, Donmiguel's paternal grandmother, said that Barber began to withdraw from family members, including her own mother.

"At one time, she stopped me from seeing him and her mother from seeing him," Sheila Phillips said of Barber.

Donmiguel was the sixth child slain in the District this year and the 30th since January 2004, a spate of deadly violence that has concerned and outraged city officials and neighborhood groups.

Julia Barber, shown in a 2000 family photo, is also the mother of an 11-month-old boy. Donmiguel Wilson, shown in a 2002 family photo, was found dead in about a foot and a half of water in the bathtub, his ankles and wrists bound.