Ghetto riot behavior is described under the categories of looting, arson and firebombing, property destruction, attacks on persons, weapons fire, and vehicles or objects used against control forces. The riot process as a whole is portrayed, and white and black attitudes toward the rioting are reported, based on surveys. A consideration of criminal influences on rioting does not indicate that criminal motives had a significant influence on rioting behavior; neither were there indications of a subversive conspiracy. Among the rioters, there are indications that some were riot-prone, exhibiting the personality configurations of a psychopath, a sociopath, or a person who is emotionally infantile. The psychological influences nurturing the rioting were primarily associated with the dynamics of crowd behavior, which provided anonymity, impersonality, suggestibility, emotional contagion, imitation, release from repressed emotions, novelty, and numbers. Social rejection and containment of blacks appears to be involved in the rioting, particularly in attacks upon law enforcement personnel, who represented to the rioters the repression of dominant white society. The various theories advanced to explain the rioting are (1) the riffraff theory, which holds that rioters were primarily irresponsible deviants; (2) the relative-deprivation theory, which argues that rioters were expressing a frustration about not progressing rapidly enough toward socioeconomic aspirations; and (3) the blocked-opportunity theory, which maintains that the riots stemmed from anger attributable to discrimination shown against blacks by whites blocking their achievement in education and employment. The blocked-opportunity theory was the only one found to have significant validity from the evidence. Sixty-nine references are listed.