next part; In Mr. Roberts' case, the United States District Court for the Eastern District of California found that prosecutors "suppress[ed] exculpatory evidence, suborn[ed] perjury, and present[ed] evidence the prosecutor knew or should have known was false" in the killing of a corrections officer. Mr. Roberts is the ninth person to be exonerated after being wrongfully convicted and sentenced to death for a murder that took place while they were incarcerated on unrelated charges. Sadly, the two cases are far from unique. Rather, they reflect a persistent pattern in innocence cases. Official misconduct and perjury/false accusation are the two leading causes of wrongful convictions that put people on death row. Official misconduct was present in 142 exonerations (71.0% of cases) and perjury/false accusation was present in 137 exonerations (68.5% of cases). More than half of the cases involved both misconduct and perjury (111, or 55.5%), and one or the other or both were factors in 84.0% of the cases (168)