The modern tribal court systems began with the passage of the Indian Reorganization Act in 1934. That Act encouraged the establishment of constitutional forms of tribal governments with tribally controlled judicial systems. By 1934, however, most tribes were not in a position to resurrect the traditional forms of justice that had functioned prior to the Courts of Indian Offenses era because of removal, dissipation, decimation through war and disease, and suppression. Instead, tribes established judicial systems that were very similar to the model urged upon them by the Bureau. Written laws were adopted and enforced while unwritten customary law was suppressed. As a result, the modern tribal courts took on practices based on Bureau offered notions of Anglo justice rather than on tribal customs.
Although some modern tribal courts are structured under specific tribal constitutional guidelines, tribal courts are typically established by tribal councils under the general authority of a tribal constitution. Procedures for tribal courts are commonly defined by the councils in the form of ordinances, but tribal court procedures may be rules created by the court itself. Judges are typically either elected by the membership or appointed by tribal councils. Tribal court proceedings may be less ridged and formal than those in the Anglo system. Indian tribes are not bound by a requirement to separate tribal government into executive, legislative, and judicial branches, and in Alaska, it is not uncommon for tribal councils to also serve as tribal courts.
Although tribal courts have a wide range of independence in terms of structures and procedures, they are all required to follow the guidance of the Indian Civil Rights Act, which is similar to the United States Bill of Rights, and passed Congress in 1968. Decisions of any type of tribal court system that result in the incarceration of someone are subject to review by the federal courts through a writ of habeas corpus which is a procedure to review the legality of an individual’s confinement. In these cases, the federal courts review cases upon request to determine if there were violations of the equal protection and due process requirements of the Indian Civil Rights Act.