Leo Hershfield, 75, dean of courtroom artists who became nationally known for his drawings of the 1954 Army-McCarthy hearings for NBC-TV, died of a heart attack Tuesday in Sarasota, Fla., while on a fishing trip.

The first of the courtroom illustrators for television, Mr. Hershfield was associated with NBC-TV throughout his career. He sketched many of this country's most conspicuous trials since the 1950s for NBC-TV, most notably those of Bobby Baker, Jack Ruby, James Earl Ray and Lt. William L. Calley Jr. His most recent television illustrations were for the trial of former U.S. representative Otto Passman (D-La.) in March.

He began his career as a newspaper illustrator in New York City, and in recent years frequently contributed to the St. Petersburg (Fla.) Times.

He also illustrated more than a dozen books, most of them humorous. In the 1950s, he painted covers and other illustrations for the now defunct Democratic Digest, then the voice of the Democratic Party.

Mr. Hershfield was born in Tennessee. He was trained at the Art Students League and the National Academy of Design in New York City and also studied abroad.

During World War II, he was an official of the Office of War Information here. He lived in Alexandria from about 1941 until moving to Bradenton, Fla., in the late 1950s.

Survivors include his wife, Mary Emma, of the home in Bradenton; two sons, Maj. Peter H., of Whiteman AFB. Mo., and Sam C., of Dayton, Ohio; two sisters, Grace Hershfield and Emily Garry, both of Chattanooga, Tenn., and three grandchildren.