Robert S. Ross Jr., a corporate lawyer who became a top aide to Richard L. Thornburgh as Pennsylvania governor and U.S. attorney general, died Sept. 30 at his home in the District. He was 69.

The cause was a pulmonary embolism, said his wife, Louise Ross.

Mr. Ross worked in New York and Washington before becoming deputy counsel to Thornburgh (R) in 1979. After a few years, Mr. Ross became a partner in a Philadelphia firm. From 1988 to 1991, he was executive assistant to Thornburgh during his tenure as attorney general.

Afterward, Mr. Ross remained in the District while serving of counsel to Cozen O’Connor, a Philadelphia-based law firm. Last year, he started a lobbying practice.

Robert Swain Ross Jr. was born in Bryn Mawr, Pa., and raised in Haverford, Pa. He was a 1966 art history graduate of Princeton University, where he played on the varsity soccer team. He was a 1970 graduate of Temple University law school in Philadelphia.

He completed more than 30 marathons, including a dozen in Boston.

Survivors include his wife of 47 years, Louise Potter Ross of the District; two children, Jennifer McNulty of the District and Robert S. Ross III of Dix Hills, N.Y.; two brothers; and five grandchildren.

— Adam Bernstein