In Greer v. Beto, the Supreme Court of the United States reviewed a case involving an inmate named Greer who was convicted for murder in Texas and sentenced to death. The main issue at hand was whether or not his constitutional rights were violated during his trial due to inadequate representation by counsel. Specifically, it was argued that his lawyer failed to object when the prosecution introduced evidence from another crime he had committed previously which may have prejudiced the jury against him. However, upon review, the Supreme Court ruled 7-2 in favor of Beto (the Corrections Director), stating that there wasn't enough proof showing that better legal representation would have changed the outcome of Greer's trial significantly. Therefore, they concluded that no violation of Sixth Amendment rights occurred.

In the dissenting opinion for Greer v. Beto, Justice William O. Douglas argued that the petitioner's constitutional rights were violated when he was not allowed to cross-examine a key witness in his trial. The witness had made statements implicating Greer in a murder, but then refused to testify at trial on Fifth Amendment grounds. The prosecution used these statements as evidence against Greer without giving him an opportunity to challenge their veracity through cross-examination. According to Douglas, this denied Greer his Sixth Amendment right "to be confronted with the witnesses against him." He also noted that there was no compelling reason why the state could not have granted immunity to the witness so they could testify without fear of self-incrimination - thus allowing for proper cross-examination by defense counsel.