In 1988, the case Adkins v. Martin, 699 F. Supp. 1510 (W.D. Okl. 1988), challenged the discipline resulting from an institutional urinalysis testing program that detected the plaintiff's alleged use of contraband drugs due to a minor error in processing. The court ruled that the inmate was required to exhaust his administrative remedies before filing a habeas corpus petition to challenge the discipline. In 1989, there were a number of cases relating to procedural issues in prisoner disciplinary actions. These cases involved discrimination against handicapped persons, habeas corpus, civil rights, and due process. The five cases dealt with in 1990 related to procedures on habeas corpus, due process, and civil rights.