Lorraine Whitlock, 83, a civic activist known for her uncompromising voice and political pull in the Deanwood community of Northeast Washington, was fatally stabbed yesterday morning by her 60-year-old son, police said.

Whitlock was stabbed multiple times in the chest in a room on the second floor of her home, and her husband, Baldwin Whitlock, 83, was cut and slightly wounded. Police said their son, William Howard Whitlock, later told them he had become increasingly annoyed by sharing the home with his elderly parents.

The younger Whitlock was arrested, police said, and charged with first-degree murder while armed. He is scheduled to be arraigned today in D.C. Superior Court.

Lorraine Whitlock, a former teacher, had been politically active for decades and helped generate support east of the Anacostia River for Marion Barry and Anthony A. Williams during their rises to political power. She later feuded with both mayors, believing they had not lived up to their promises.

"If she disapproved of something, you knew," said former D.C. Council member H.R. Crawford. "Mrs. Whitlock could not be bought. Mrs. Whitlock could not be persuaded to do anything that was going to affect the people in her area adversely."

Williams issued a statement yesterday saying that he was "shocked and greatly saddened" to learn of Whitlock's death and that her commitment to the community "set the standard for all who strive to make a difference in the world."

Over the decades, Whitlock focused on education, but she was apt to take on a variety of causes, those who knew her said. She was a former trustee at the University of the District of Columbia. Lately, she had been fighting a plan by Habitat for Humanity to build homes on a low-lying piece of ground that residents called "the Swamp."

"Our problem is not with Habitat for Humanity," she told a Washington Post reporter last April. "Our concern is that nobody should put homes for anyone on that land."

Political observers remembered Whitlock as someone rooted in "the real Washington." Married to the city's first black motorcycle police officer, she spoke for a middle-class neighborhood where police officers and schoolteachers lived. In the fast-changing landscape of city politics, her death was mourned yesterday by several generations of politicians and activists.

"I'm just numb," said D.C. Council member Kevin P. Chavous (D-Ward 7), who represented her neighborhood and often found himself at odds with Whitlock. "This is just a tremendous loss for the whole city. She was just a giant for the community."

"She called it like it was," said council member Carol Schwartz (R-At Large), whom Whitlock supported in the last mayoral election. "I mean, what a loss."

About 8:15 a.m. yesterday, police and firefighters were summoned to Whitlock's three-story rowhouse in the 500 block of 48th Place NE. They found Whitlock's husband and son downstairs and Whitlock lying on a bed on the second floor, with numerous bloodstains on her clothes, according to a source familiar with the scene.

She was taken to Prince George's Hospital Center, where she was pronounced dead at 8:50 a.m. Her husband had minor injuries, police said, and was treated in the home.

Police quoted William Whitlock as saying that his annoyance with his parents had been building since the beginning of the year. One investigator said he attacked them because of his anger over "issues of him living with his parents, because they're too elderly."

There have been 68 homicides in the District this year, an increase of 17 percent from the same time last year. Whitlock's killing was the ninth in the city since Sunday, a chilly week of suspended spring that also has been marked by five homicides in Prince George's County.

Reached at his home yesterday, Whitlock's husband declined to talk about what happened.

"We had a death in the family," he said. "And it's too early to talk about it right now."

Staff writer Yolanda Woodlee and staff researcher Bobbye Pratt contributed to this report.