D, Wagner, and Broder were indicted for conspiring to buy and receive certain checks and letters which had been stolen from duly authorized depositories for mail matter. Broder pleaded guilty. He was then called as a witness for P. Ds objected on the grounds that Broder was not competent to be called as a witness. The reason being that Broder had pleaded guilty to forgery in another case. D relied on the common law rule that party convicted of forgery was incompetent to testify until pardoned. The court permitted Broder to testify. Ds were convicted and appealed, and the Circuit Court of Appeals affirmed. The Supreme Court granted certiorari.