A 60-year-old Interior Department official was shot and killed and his wife was wounded at their Silver Spring home last night by an assailant they apparently knew well, police said.

Frederick Fishman, an administrative law judge, was found shortly before 7 p.m. lying in the driveway of his home at 9832 Cherry Tree La., with several gunshot wounds in his upper body.

His wife, Evelyn, also 60, was shot in the neck. She was found in a front yard two doors from the home after neighbors in the quiet area had been startled by a volley of gunshots.

Police said last night they had no suspect in custody and had not issued any warrants. But they were trying to find the Fishman's son, Lawrence, 29, for questioning, according to Cpl. Phillip Caswell, a Montgomery County police spokesman. Caswell said the son had been at the house last night and had left after the shooting.

Investigators said they knew of no motive in the incident.

One colleague of the slain official said he believed there had been recent friction between father and son. He said Lawrence Fishman was a Phi Beta Kappa graduate of the University of California who also graduated from the University of California law school.

According to the colleague, the son had left the Washington area for Philadelphia about four weeks ago after an argument with his father.

"Apparently they [father and son] did not get along that well," said the colleague, who did not wish to be identified.

Both Fishman and his wife were taken to Sururban Hospital, where the husband died at 9 p.m. The wife was listed in good condition.

"We are rather in shock," said one resident of the neighborhood just north of the Beltway and west of Northwest Branch park. "My husband and I were eating dinner very quietly. We heard several loud shots, then two minutes later we heard some more. . . ."

The woman said her husband looked outside, saw Fishman and told her to call the police.

Fishman, an administrative judge in the Board of Land Appeals since 1972, spent almost 40 years in government service.

He entered law school directly after graduation from a prestigious Boston secondary school.

The family was struck by tragedy two and a half years ago when an older son, Richard, 30, who went to Israel to study, was killed when a bomb exploded on a bus.

The Fishmans' third child, a daughter, Ruth, lives in California.