A 12-year-old boy has become the city's latest victim of what police believe to be drug-related violence, but a day after the shooting deaths in a Stoddard Terrace home in Southeast neither investigators nor the boy's family would say what happened or why.

Mark Settles, a sixth grader at Weatherless Elementary School, a Boy Scout, church choir member and tackle on a Little League football team, was found lying in a pool of blood in his home Thursday. His dog, Old Cyrus, was lying next to him, also shot dead. Mark's little brother, John Settles, 2, had been sleeping in an upstairs bedroom at the time of the slayings.

John Settles, 24, Mark's uncle and the only adult in the house, suffered a superficial wound in the leg.

John Settles was treated at D.C. General Hospital and checked out yesterday. Later in the day, police investigators interviewed Settles, whom they had interviewed initially in the hours after the shootings.

Early reports that Mark Settles may have been caught in a dispute between his uncle and drug dealers may prove untrue. Police sources said they are still investigating how drugs figured into the killings.

There are three types of drug-related homicides: slayings motivated by revenge or turf wars; drug deals gone sour, or killings, often bizarre or extraordinarily brutal, committed by people who are high on drugs.

Asked if John Settles was involved with drugs, one of his sisters, Karen Settles said: "I don't know. I really can't say."

The 200 block of 37th Place SE where Mark died is a hilly street ending in a cul-de-sac. It is lined with two-story brick apartment buildings pocked by broken windows and graffiti. Garbage is abundant on the ground. Boys and men line the street.

"This is the projects," said Harry Brittingham, 21, a neighbor of Mark's. "People make money the best way they can."

Violence is a way of life, residents said. Here, ice cream vendors do business with wire mesh over the windows of their trucks and bars protecting countertops from hands that might reach in and steal.

"There's always trouble," said Eleanora Settles, 27, Mark's mother, who is an inserter for The Washington Post. But Mark, she said, stayed clear. Still stunned by his death and the sight of him lying motionless on the kitchen floor, she was surrounded yesterday by several of her sisters and a brother who fiercely shielded her from questions. She has lived in Stoddard Terrace for 18 years.

About 2 p.m. Thursday, she walked down the hill to her sister Karen Settles' house. Mark was home from school that day because of an eye infection.

According to the account that John Settles gave to the family, which Karen Settles retold yesterday, this is what happened: John Settles was in a downstairs bedroom of the Settles apartment.

"John heard a knock at the door, and he had Mark go see who was at the door," Karen Settles said. John Settles then heard gunshots and started toward the kitchen. "He told me he only saw a hand coming around the china closet." He was shot and then passed out, Karen Settles said.

When Eleanora Settles returned home at 3:25 p.m., she opened the back door and saw the motionless bodies and the blood.

"I didn't come in," she said. "I thought, 'My baby's dead.' "

She went back down to her sister's home and the two returned to the scene together. Karen Settles said she went into the apartment and, along with Mark and the dog, she saw John Settles on the floor. Apparently, neighbors had called police, she said.

Settles and her sisters said that on a street where people routinely peer out of their windows, it is hard to believe that no one saw unusual comings and goings at the apartment.

One neighbor reported to them that she had seen a green Mustang parked on the street with two men inside, Karen Settles said. The woman noticed it because the car was unfamiliar. She saw the car speed away around the time that the shootings occurred. And some of the boys on the street said they heard gunfire. But there, the witnesses end.

"It's not possible that nobody saw anything," Karen Settles said. "They've got to stop being quiet because it's not helping anybody."

The family also was upset that they rarely saw officers in a police community services office that had been set up across the walk from their apartment.

The office opened during the summer as a way of helping police establish a rapport with the community, said Capt. William White III, a police spokesman. It was not intended to be open every day.

Residents out on the street, near the remnants of yellow police crime scene tape that had roped off the apartment, said they were sad that Mark was killed. Francisco Brittingham, 13, said Mark was his best friend. He stayed home from school yesterday because "I hate to see school without him being there."

Many other youths who also were not in school jockeyed for position in front of television news cameras. Women, some in nightclothes, scurried out into the cold to talk to neighbors. A boy ran a remote-controlled car in the middle of the street. A 17-year-old who called himself Dee-Boo pulled some $100 bills from his pocket to show to reporters. In the building behind him, where the stench of human waste fills the stairwells, a 32-year-old mother of six peeked out of her window.

Betty Gaskins, 42, who has lived in Stoddard Terrace for 22 years, characterized the attitude of the area's youth this way.

" 'This is life,' you'll hear them say. 'That's the way it is.' But this isn't life. This isn't life when you have a 12-year-old child getting shot."

Staff writers Victoria Churchville and Carlos Sanchez contributed to this report.