A 17-year-old youth, described as a good student and a member of a respected family, was arrested yesterday and charged with fatally stabbing an older brother in their home in the District's Takoma Park section.

D.C. police said the victim, 26, was stabbed in the back with a butcher knife about 1:30 p.m. during an argument. He was taken in critical condition to the Washington Hospital Center, where he died about two hours later.

The immediate subject of the dispute could not be learned last night. However, one homicide detective said the older brother had been beating the younger for years.

Neighbors interviewed last night said that the family had lived quietly for more than 20 years in the area of detached brick homes with spacious yards.

One of the neighbors, who declined to be identified, described the 17-year old, one of five children of a guard at a museum here, as a "very nice young man," for whom the alleged stabbing was "completely out of character."

Neighbors described the victim as distinctly less gregarious than the 17-year-old and his other brothers and sisters, who were said to be particularly friendly, outgoing and eager to perform chores. One neighbor said it was believed the victim had suffered from an illness.

Police said the 17-year-old was charged with homicide.