D.C. police are close to solving the case of a 6-year-old boy who was found dead, bound and gagged, in a bathtub yesterday in a Southeast Washington apartment, a police official said today.

"I would say an arrest is going to be forthcoming," Capt. C.V. Morris, head of the Metropolitan Police Department's violent crimes branch, told reporters. He indicated that the suspect is a member of the boy's family but said the motive is not clear.

The boy, Don Miguel Wilson, appeared to have been dead for hours, perhaps longer, when his grandmother found him at 8:15 a.m. yesterday, face down in about a foot and a half of water in the bathtub, police said. The grandmother had come to pick him up for summer camp and called 911.

Police said the child lived in the apartment with his mother, Julia Barber, and his 11-month-old brother. Investigators questioned the mother last night, and the 11-month-old was in the care of the city's child welfare agency.

Asked by reporters to identify a suspect in the case, Morris today declined to provide a name but indicated that police believe a family member was responsible.

"We have identified all the family members," he said. "We believe it has to deal with that family. It's nothing that's an outside source."

Morris said, "I can't rule out the mother; I can't rule out anybody."

The mother was questioned into the early morning hours and released, police said.

"I'm pretty confident we should be able to close this case very soon," Morris said.

He said that "we want to make sure we have everything in order" before detectives move ahead with an arrest. Police are awaiting the results of an autopsy and trying to corroborate what they already know before taking that step, Morris said.

The boy's grandmother, Juanita Barber, told police that the front door of the apartment was unlocked, which she said was unusual. When she found Don Miguel, his ankles were bound, his hands were tied behind his back and some kind of gag was in his mouth, police said. He was wearing play clothes, they said.

Relatives and others described Don Miguel as an energetic, affectionate, high-spirited youngster who enjoyed sports, electronic toys and helping work on a relative's car.

"This is beyond tragic. It's something that should anger anyone, that a youngster could be so sadistically killed," D.C. Police Chief Charles H. Ramsey said.

Police were attempting to determine why the boy was alone and for how long. They said Julia Barber was with Don Miguel's brother and came to the scene after being contacted by the grandmother. Police provided no other details about the mother's whereabouts. One relative said Julia Barber is a nursing assistant.

Don Miguel was pronounced dead in the second-story bathroom of the brick apartment building he'd lived in for most of his life. For hours, the crime scene investigators had to work around his body. Medical examiners finally removed the body late in the afternoon.

The medical examiner's office is conducting the autopsy to determine time and cause of death. Investigators said the stages of rigor mortis might have been hastened by the water, making it difficult to quickly establish a time of death, Ramsey said.

Some of the victim's relatives gathered at the police department's violent crimes branch, where detectives were questioning the mother and others in hopes of uncovering leads.

Brazil Smith, the boy's maternal great-grandfather, often cared for the child during the day.

He said that Don Miguel and his younger brother were very close.

When he dropped Don Miguel at his mother's house each night, Smith said, the younger brother would bypass Smith and go right to Don Miguel. "Don was crazy about his little brother, and his little brother was crazy about him."

He remembered the youngster as a "vibrant, all-American boy," and he also praised the boy's mother, whom he described as an "outstanding parent." She was always doing things for her children, Smith said.

A great-aunt, Patricia Smith, recounted how Don Miguel would fearlessly approach her mastiff and how he would jump around with a towel wrapped about him, imitating Superman.

At his home in Southeast Washington, Donmiguel Wilson Sr., the boy's father, was accepting condolences and trying to fathom what happened. He said he had separated from Barber about two years ago. He saw his son regularly, he said, and they last got together on July 4.

"I'm still kind of blurry up top," Wilson said. "It's hard to believe. Somebody killed my son. Somebody murdered my child."

Wilson said young Don Miguel "would just run to me and hug me tight. . . . I can see him running up the street right now."

The boy was to begin the second grade in September at M.C. Terrell Elementary School, just down the street from his apartment in the 3200 block of Wheeler Road. Neighbors and others who knew him said Don Miguel liked to play football, basketball and video games and often tore around the courtyard on his bicycle.

They said he was polite and friendly at home and at school, recalling how generous he was with his hugs.

"Don Miguel was a nice child, very loving," said Anitha Davis, an administrative assistant at Terrell. "He would always give me a hug before he left for home."

"I really don't know what to make of this," said Andrew Haltiwanger, who lives in the apartment complex. "He was just a happy little boy, and they seemed like a happy family."

Other residents said the area, known as Congress Heights, has long been known as a dumping ground for stolen cars. There have been some drug problems and occasional violence, they said, but nothing to match yesterday.

"Even with all the crime we see in the District, you don't really see children targeted like this," said community activist Sandra Seegars.

Don Miguel was the sixth juvenile slain this year in the District, the 30th since January 2004, a spate of violence that has outraged city officials. The most recent previous casualty was Donte Manning, 9, who was fatally shot in March while playing outside his apartment in Northwest Washington.

Ramsey noted that Donte appeared to be hit by random gunfire, adding, "Unlike Donte Manning, this clearly was intentional."

Staff writers Henri E. Cauvin, Allan Lengel and Martin Weil and staff researcher Bobbye Pratt contributed to this report.