D.C. police and prosecutors reviewed videotaped statements and other evidence yesterday as they continued to investigate the slaying of a 6-year-old boy who was discovered dead in a bathtub, authorities said.

The boy's mother, Julia Barber, 27, was being evaluated at a District psychiatric facility, where she was taken early Tuesday after being questioned by detectives investigating the killing of her son, Donmiguel Nathaniel Wilson Jr.

D.C. police officials said she is a suspect in the boy's slaying.

Donmiguel was discovered in his apartment's water-filled bathtub Monday morning by his grandmother. His ankles and wrists were bound with cloth, and he was facedown, under a pillow and blanket. Police officials said the boy probably was tied to prevent him from fleeing or fighting back.

The city's medical examiner has ruled the case a homicide and determined that Donmiguel died of a combination of drowning, suffocation and head injuries, officials said.

Capt. C.V. Morris of the D.C. police violent crimes branch declined to discuss specifics of the case yesterday. He also would not elaborate on statements made to reporters Tuesday in which he said detectives were focusing on the boy's family and did not believe an "outside source" was responsible for Donmiguel's death.

"We are just reviewing the evidence we have, the statements we have," Morris said yesterday.

Barber, who lived in the apartment with Donmiguel and an 11-month-old son, was questioned for several hours after the body was discovered.

She complained about the stress of being a parent and how Donmiguel was not happy with her boyfriend, who relatives said is the father of the younger child, authorities have said.

Relatives of the boy's father have described Barber as acting strangely in the past week and said she complained about voices and talking to the Devil.

Barber's statements were rambling, but detectives believe that they implicate her in the boy's death, police officials said. She also had a conversation with her mother about the boy's death that was recorded on videotape, officials said.

Worried about her mental state and the possibility of suicide, authorities had Barber admitted to a psychiatric facility on the grounds of the former D.C. General Hospital.

No charges have been filed in the case. A spokesman for the U.S. attorney's office said detectives have not presented an arrest warrant in the case, contradicting a report yesterday in The Washington Post that cited police officials.

However, prosecutors are helping review evidence and working closely with police detectives, said the spokesman, Channing Phillips.

Authorities said they do not expect charges to be filed until today or Friday at the earliest.

Donmiguel was the sixth child killed in the District this year, the 30th since January 2004. His killing shocked relatives and community members. Neighborhood activists said they will hold a candlelight vigil at 8 p.m. today in front of Donmiguel's apartment building, in the 3200 block of Wheeler Road SE.

"We want to show respect to the family and to him," said Sandra Seegars, a neighborhood advisory commissioner who represents the area. "It's about supporting the family. It's about letting them know that we know their pain."

Julia Barber has implicated herself in her son's death, detectives have said. She is being evaluated at a psychiatric facility. Six-year-old Donmiguel Wilson was found, wrists and ankles bound, face down in bath water at his home.