David E. Betts, 71, a Rockville attorney and a former president of the Maryland State Bar Association, died of cancer July 16 at his home in Rockville.

Apart from his practice in the firm of Betts and Murdoch, which specializes in real estate law, Mr. Betts had been counsel to the treasurer of Montgomery County, the city attorney of Rockville and the general counsel of the Rockville Volunteer Fire Department. He was a former president of the Montgomery County Bar Association.

Mr. Betts was born in Chicago and reared in Chevy Chase. He graduated from McKinley Technical High School in Washington and Norwich University in Northfield, Vt. He earned his law degree at George Washington University. He began his practice in Rockville in the late 1930s.

During World War II, he served in the Army Air Forces and rose to the rank of lieutenant colonel.

He was a director of the Suburban Bank and the Suburban Mortgage Co., a vice chairman of the board of trustees of Suburban Hospital and a president of the board of trustees of Rockville Academy.

He was a warden and vestryman of Christ Episcopal Church and sang in its choir for 45 years. He also appeared in many Gilbert and Sullivan operettas and in the Rockville Little Theater.

Mr. Betts was a member of the Burning Tree and Chevy Chase clubs, the Maryland Club in Baltimore, the Farmington Country Club in Charlottesville, Va., and the Ha'Penny Beach Club in St. Croix, V.I.

Survivors include his wife, Maude (Sis), and a daughter, Barbara B. Cromwell, both of Rockville, and three grandchildren.