John Sullivan (defendant) was indicted along with two other defendants for murder. The defendants were all represented by the same lawyers. Neither Sullivan nor his lawyers objected to the multiple representation. Sullivan was the first defendant tried. After the prosecution’s case, the defense rested without presenting any evidence. Sullivan was convicted and sentenced to life while the other two defendants were acquitted. Sullivan filed a petition for collateral relief and argued that he received ineffective assistance of counsel because his lawyers’ representation of the other two defendants created a conflict of interest. One lawyer stated that he had encouraged Sullivan to testify, while the other lawyer stated that he did not want Sullivan’s defense to go on because it might have affected the other two defendants’ upcoming trials. Sullivan claimed he deferred to his lawyers’ advice, but there was evidence that he chose not to testify to avoid exposing an affair. The lower court made no decision on the conflict of interest claim, but found that Sullivan was adequately advised about not testifying. All other claims for relief were denied. The state supreme court affirmed Sullivan’s conviction and the denial of relief. Sullivan filed for a writ of habeas corpus and his petition was referred to a magistrate. The magistrate found that Sullivan’s lawyers had a conflict of interest, but the federal district court found that there had been no multiple representation. The court of appeals reversed. The Supreme Court granted certiorari.