Lawson (defendant) was detained or arrested fifteen times between 1975 and 1977 for violation of a California statute requiring street loiterers to provide “credible and reliable identification” to officers who asked for the identification. Of these fifteen detainments and arrests, Lawson was convicted only once. After his conviction, he brought a civil action in district court in order to have the statute declared unconstitutional. The district court declared the California statute unconstitutional and the court of appeals affirmed the district court. The court of appeals found that the statute had no specific enforcement standard and that it also failed to “give fair and adequate notice of the type of conduct prohibited” as required by the Fourteenth Amendment’s due process clause. The United States Supreme Court granted certiorari.