Donald P. Libera Sr., 85, who in 1939 joined what is now the District of Columbia Housing Authority and retired in 1976 as director of administration, died of cerebral vascular disease Dec. 3 at Arlington Hospital. He lived in McLean.

Mr. Libera was born in Dodge, Wis., and graduated in 1935 from Saint Mary's College of Minnesota with a bachelor's degree in economics and business administration. In 1950, he received a law degree from Georgetown University.

He moved to the Washington area in 1936 to work at the FBI for two years as an assistant fingerprint classifier. He then was at the Bureau of Labor Statistics for a year as an assistant statistical clerk before joining what was then the Alley Dwelling Authority as a chief statistical clerk. When he retired, the agency was known as the National Capital Housing Authority.

After retiring, he volunteered at the Arlington County senior adult program.

He was a member of the National Association of Housing and Redevelopment Officials and the Edward Douglas White Council of the Knights of Columbus in Arlington.

Mr. Libera also was a member of St. John's Catholic Church in McLean and a principal at its religious education program. Other Catholic organizations he belonged to included Christian Family Movement, Teams of Our Lady and McKenna House.

He played saxophone and clarinet in local bands, including Dawne Tance, a Polish folk ensemble.

During World War II, he served in the Marines in the Pacific. He retired from the Marine Reserve in 1974 as a lieutenant colonel.

Survivors include his wife of 57 years, Helen Libera of McLean; four sons, Don Libera Jr. of Manassas, Stephen P. Libera of McLean, Thomas V. Libera of Vienna and John J. Libera of San Jose; a daughter, Jeanne Kidwell of Warrenton; a sister; nine grandchildren; and a great-granddaughter.