Three people were killed and four others were wounded, two critically, in separate incidents in the District Friday and yesterday, police said.

The violence began about 9 p.m. Friday with the stabbing death of an unidentified man in the 1200 block of I Street SE and included the wounding of a 17-year-old youth who allegedly aimed a shotgun at an off-duty police officer early yesterday.

The youth, whose name was not released because his family has not been notified, was in stable condition at D.C. General Hospital yesterday, officials said. The shooting took place on the 4900 block of East Capitol Street SE outside a recreational center run by St. Luke's Catholic Church. Police said the off-duty officer, Bruce Faison, saw the youth pull a shotgun out of his pants.

Faison identified himself as an officer, police said. When the youth pointed the shotgun in his direction, Faison fired once, striking the youth in the abdomen, police said.

In another incident, in the 1400 block of Congress Place SE, the boyfriend of a 21-year-old woman burst into her house at 5:30 a.m. yesterday and shot her and her mother, police said. Virginia Page was taken to D.C. General Hospital, where a spokeswoman declined to release any more information because no one had been arrested. Katherine Page, 42, was shot in the head and was in critical condition yesterday at Washington Hospital Center. Police have no motive.

Police released the identity of only one of three homicide victims, and in all three cases there are no suspects or motives. The dead man was identified as Russell Savoy, 26, who was stabbed to death last night in an alley behind the unit block of Galveston Street SE. The body of an unidentified stabbing victim in his thirties was found in the 1200 block of I Street SE about 9 p.m. Friday.

Yesterday, police were investigating the 4:15 p.m. shooting death of an unidentified man in the 4400 block of Deane Avenue NE. Also yesterday, an unidentified 25-year-old man was stabbed about 2:35 a.m. in the 700 block of Taylor Street NW. He was in critical condition at Washington Hospital Center.