The weaknesses in the criminal justice system exposed by these cases led to the establishment of a Royal Commission on Criminal Justice in 1991. Its mandate included considering whether changes were needed in the arrangements for considering and investigating allegations of miscarriages of justice when appeal rights have been exhausted. Evidence was gathered over a two-year period. The Royal Commission published its report in July 1993. It concluded (adopting the view expressed by Sir John May in his inquiry into the Guildford and Woolwich bombings) that the arrangements for referring cases back to the courts were incompatible with the constitutional separation of judicial and executive powers. The recommendations of the Royal Commission led to the Criminal Appeal Act of 1995, which established the Criminal Cases Review Commission.