The Detroit riot, which began on Sunday, July 23, 1967, produced such jail overcrowding that 200 arrested rioters were transferred to the Federal Correctional Institution, Milan, Mich. These 200 men composed the sample for this study. The 200 were selected randomly for transfer, so the sample is probably representative of those who participated in the riot. All were arrested on the first day of the riot, however, which may perhaps have distinguished them from those who entered the riot later. A total of 187 of the men were interviewed, and the work sheets of the legal services interviews were available for 144 of the 187 respondents. Information was obtained on work, age, marital status, housing, living arrangements, knowledge of and participation in community programs, education and vocation preparation, and criminality. While unemployment and underemployment were substantial problems for many of the men, the majority were steadily employed for adequate wages (median salaries were over $100 for a 40-hour week). Educational levels were relatively high, and many had received vocational training. Most lived in adequate housing, and the majority of the married men were living with their families. Many were without prior arrest records and convictions. Most lived over a decade in the Detroit area and showed residential stability within the urban enclave. This information parallels the findings of a similar study of Watts rioters (Los Angelas area). Since these findings contradict popular conceptions that riots are precipitated by extremely deprived living conditions and an absence of opportunuity for socioeconomic betterment, there is a need for a rethinking of riot causes based on the empirical data available. Tabular data are provided.