Medina (D) was involved in four robberies and three murders. He was then charged with three counts of first-degree murder. He claimed that he was incompetent to stand trial due to mental illness. There were different expert opinions, each concluding differently. The jury found that D was competent. D was tried, convicted, and sentenced to death. D appealed, claiming that California was not constitutionally allowed to give him the burden of proving that he was incompetence. The California Supreme Court rejected D's appeal. The United States Supreme Court granted review.