George E. McMullin, 65, who retired in August as an investigator for the D.C. Department of Human Resources, died of cancer Thursday at Northern Virginia Doctors Hospital. r

A native of Philadelphia, Mr. McMullin was an agent for the Sun Life Insurance Co. of America there. He transferred to Arlington in 1950, when he became a field manager for the company. He joined the Department of Human Resources in 1967.

Mr. McMullin attended St. Joseph's College in Philadelphia. He served in the Army in Europe during World War II.

He was a member of the Edward Douglas White Council 2473 of the Knights of Columbus in Arlington, the Col. John Fitzgerald Division No. 1 of the Ancient Order of Hibernians, the Arlington chapter of the American Legion, the Elks and the Sons of Italy.

Mr. McMullin's first wife, the former Evelyn C. Kevit, died in 1972.

Survivors include his wife, Alice C., of the home in Arlington; three daughters, Lynn Abell, of Falls Church, and Joan M. Buscher and Judy M. Koumarianos, both of Arlington; a stepdaughter, Joan Fisher, of Annandale; six stepsons, Louis Caruso, of Annandale, Jim Caruso, of Cleveland, John Caruso, of Marshall, Va., Paul and Kevin Caruso both of Vienna, Va., and Stephen Caruso, of Alexandria; two brothers, John, of Riverside, Calif., and James, of Warminster, Pa.; five sisters, Gertrude Ludwig and Dorothy Kelly, both of Philadelphia; Sister Camillus, I.H.N., of Trenton, N.J., Helen Keane, of St. Petersburg, Fla., and Mary Carroll, of Rosemont, Pa., and 11 stepgrandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.