Richard S. Winstead, 61, an Army colonel who retired in 1975 as commanding officer of the Army Security Agency's combat development activity, died of cancer Friday at the Walter Reed Army Medical Center.

After serving in Hawaii during World War II, Col. Winstead earned a law degree from Georgetown University. He then became editor of the U.S. Supreme Court Bulletin for Commerce Clearing House Inc. until 1951, when he was recalled to active duty.

He joined the Army Security Agency and was first commanding officer of the 502nd communication reconnaissance group at Fort Devens, Mass., and in Germany. He subsequently saw duty in Korea, Thailand, Japan and Okinawa. His last assignment was with the agency's combat development activity.

Col. Winstead, who lived in Annandale, was born in Boise, Idaho. He graduated from Whitman College and attended the University of Michigan.

His military decorations include the Legion of Merit with three Oak Leaf Clusters.

Survivors include his wife, Dolores B., and a daughter, Laurie D., both of the home; another daughter, Sharon A., of Norfolk, Va.; a son, Richard C. of Reston; and two sisters, Anne W. Burnam, of Everett, Wash., and Elizabeth W. Munro, of Corvallis, Ore.