William A. Kehoe Jr., 58, a retired assistant general counsel of the Federal Communications Commission, died Thursday at Southern Baptist Hospital in New Orleans, following a heart attack. He lived in Bozman, Md., and was visiting a daughter at the time of his death.

Mr. Kehoe was born in Lawrence, Mass. His family moved to Washington when he was an infant. He graduated from Gonzaga High School and earned bachelor's and law degrees from Georgetown University.

He established a private law practice in Washington in 1946. One of his cases went to the U.S. Supreme Court, which ruled in his client's favor. The case established the principle that servicemen who commit crimes while in uniform and who are not charged until they leave the service are entitled to trial in civilian rather than military courts.

In 1958, Mr. Kehoe joined the Justice Department as a trial attorney in in civil rights division. He later was assigned to the criminal division and to the department's organized crime strike force.

In the middle 1960s, he transferred to the FCC as a senior trial attorney in the agency's broadcast bureau. Despite the gradual loss of his eyesight beginning in 1969, he became an assistange general counsel.

He also lectured at Georgetown University law center and at the American Institute of Banking.

He was a member of the D.C. and Maryland bar associations and of the bar of the U.S. Supreme Court.

Mr. Kehoe lived in Chevy Chase until his retirement from the FCC in 1978. He then moved to Bozman.

Survivors include his wife, Elizabeth, of Bozman; two daughters, Susan Kohoe of New Orleans and Maureen Kehoe of Bozman; four sons, William A. III, of Kensington, Christopher, of Easton, Md., and Dennis and Stephen, both of Bozman; two sisters, Marie Darr of Washington, and Marilyn Keating of Rockville and three brothers, Edward, of Washington, Daniel, of Malibu, Calif. and Lawrence, of Kensington.

The family suggests that expressions of sympathy be in the form of contributions to the American Foundatin for the Blind, 15 W. 16th St., New York, N.Y., 10011, or to the Maryland chapter of the American Diabetes Association, 3701 Old Court Rd., Baltimore, Md. 21208.