Sammy Marshall was convicted of first-degree murder, robbery, attempted forcible rape and kidnapping, and was sentenced to death. On appeal, he contended, among other things, that there was insufficient evidence to support the jury's verdict finding him competent to stand trial.

At the competency hearing, in May, 1988, a psychiatrist for the defense testified that he attempted to interview Marshall at the jail on four different occasions; the first three times, Marshall called him names, threatened him, and demanded to be taken back to his cell. At the fourth interview, Marshall eventually proceeded to talk nonstop in a rambling manner for approximately 15 minutes. He said he was receiving religious communications from someone called the “narrator”, that there was a conspiracy to kill him, and that the conspirators included the doctor and his attorney. The doctor concluded that Marshall was not faking incompetence, opining that his symptoms matched those exhibited by psychotic patients in general, such as delusional ideas, religious paranoia, and rambling speech. He said that Marshall's ability to assist his attorney was impaired because his thinking would become delusional when asked about the details of the case. But the doctor also stated that to some extent the defendant was capable of understanding the nature and purpose of the legal proceedings. And in cross-examination, he described the defendant as fairly intelligent and articulate. He conceded that it was ‘certainly a possibility’ that the defendant could, if he so desired, cooperate with his attorney, and that certain documents he prepared indicated an ability to assist in his own defense.

The defendant refused to testify at the competency hearing. For the prosecution, a psychiatrist testified that Marshall was probably incompetent, but that it wasn't clear, and that his opinion lacked “a level of reasonable medical certainty.” He did find a strong manipulative component to the defendant's conduct. The prosecution then called lay witnesses, including the courtroom bailiff and a deputy sheriff, both of whom had seen and talked to Marshall numerous times in over a period of more than two years. Both testified that the defendant had mostly appeared coherent and rational.

The defendant contended that the evidence of his incompetence was “persuasive and virtually uncontradicted.” He pointed to the fact that there was unanimous expert testimony establishing his incompetence, contradicted only by lay testimony. But the Court disagreed, finding that substantial evidence supported the jury's verdict that Marshall was competent to stand trial. Said the Court, “Contrary to defendant's assertion, the jury did not have to accept the opinion of experts.” The Court noted that both the defense and the prosecution psychiatrists based their opinions regarding the defendant's competence on their interview with him, and said their opinion would be affected by evidence that he acted normally outside the setting of a psychiatric interview—and such evidence was presented by the lay witnesses. The Court did, however, reverse the special circumstances finding of robbery, thereby reversing the sentence of death.