William Perl (1920–1970), whose original name was William Mutterperl, was an American physicist and Soviet spy. Background While a student at the City College of New York, Perl joined the Steinmetz Club, the campus branch of the Young Communist League, where he met and befriended future Soviet spies Julius Rosenberg, Morton Sobell and Joel Barr. Perl graduated with a degree in engineering in 1939, and in 1940 began working for the National Advisory Committee for Aeronautics (NACA) at their Langley Army Air Base research facility in Hampton, Virginia. In 1944 Perl transferred to the NACA Lewis Flight Propulsion Laboratory in Cleveland, Ohio. Both jobs provided Perl with access to extensive classified materials. NACA sent Perl to Columbia University to pursue doctoral studies in Physics. While at Columbia, Perl lived in the same Morton Street apartment where Barr and Alfred Sarant had lived. Career Following his doctoral work at Columbia, Perl returned to Cleveland to work on a jet propulsion project related to supersonic flight. Perl was nearly given a position with the U.S. Atomic Energy Commission when his connection with Barr and Sarant, suspected Communists, was turned up by a security check. Rosenberg Case In July 1950, Vivian Glassman, Barr's fiancée, visited Perl in Cleveland to give him $2,000, advising him to go to Europe. Unlike Barr and Sarant, Perl decided not to flee the country, perhaps thinking he might be able to salvage his career. ACLU lawyer Raymond L. Wise "of 80 Broad Street" served as Perl's attorney. Rosenberg Grand Jury Perl appeared before the Rosenberg Grand Jury in the summer of 1950, denying any relationship with Julius Rosenberg, Morton Sobell, Max Elitcher, Ann Sidorovich, and Michael Sidorovich. By August 29, 1950, Wise was advising Perl to cooperate. On March 10, 1951, Wise and Perl met with FBI agents; Wise stated that Perl had paid him a "substantial fee" as retainer. On March 15, 1951, Perl was arrested. In April 1951, FBI advised Wise that they would make no deal with Perl over a plea of perjury. Wise argued that the Government lacked jurisdiction to indict, to no avail. The Government delayed the trial in September 1951 due to Wise's illness. In June 1952, Wise asked for a reduction in bail from twenty to five thousand dollars; the judge reserved the decision. In December 1952, Wise asked for another deferral, as he would be in Florida for the winter;