A 44-year-old associate professor of history at Howard University was found stabbed to death in his 16th Street NW apartment yesterday morning and investigators have no motives or suspects in the slaying, D.C. police said.

Police found the body of Clifton Fleming Brown shortly before 9:30 a.m. in his third-floor apartment at 2620 16th St. NW, they said.

A professor at Howard University since 1969, Brown taught courses on medieval Ethiopia, precolonial Africa, early European history and an introductory survey of the black diaspora.

Brown, an Ohio native, earned a master's degree in history from Howard in 1968, a master's in religion from the Howard Divinity School in 1972 and a doctorate in African studies from Howard in 1979.

Neighbors at Brown's apartment building said they heard no untoward noises Sunday night or yesterday morning. The eight-story building is adjacent to the Lithuanian legation and down the block from the Czechoslovakian Embassy in the Lanier Heights neighborhood.

The resident manager of the building said she discovered Brown's body and notified police.

The manager, who asked not to be identified, said one of Brown's academic associates "called [Brown's brother-in-law] and said he couldn't get in touch with Clifton and contacted me to see if there's anything wrong."

She said she then went to Brown's apartment and opened the door. "I noticed he was lying on the ground in his living area," the manager said. She said she noticed "a splatter of blood" on closet doors at the right side of the room, closed the door and called police.

Homicide investigators said it was not apparent if Brown was stabbed more than once, and they have yet to determine a motive. There were no signs of forced entry, police said.

Police sources indicated that the slaying may have been a domestic incident.

Brown was "a dynamic and rigorous teacher," said Arnold Taylor, chairman of Howard's history department. "He was a professional in his teaching and his research."

Taylor said Brown had no relatives in Washington. Aside from his teaching and writing, Brown worked with the city's Benjamin Banneker Academic High School, serving as liaison between the school and Howard.

Brown had been at work on a book tentatively titled "The Emergence of Theocratic Kingship in Medieval Ethiopia," Taylor said.

Among Brown's most important publications, he said, were a 1978 bibliographic guide to histories of Ethiopia and a bibliography of African and Afro-American religious studies published in 1977.Staff writer Marc Fisher contributed to this report.