The survey also found that younger inmates and those with more extensive criminal careers or drug histories were the most likely to have violated prison rules. Rule violations were also more common in larger prisons and maximum-security prisons and among males, but were similar for white and black inmates. In addition, more than 90 percent of the inmates charged with infractions were found guilty in prison administrative proceedings, regardless of inmate or prison characteristics. Furthermore, inmates serving their first prison sentences had a lower infraction rate than did recividists. Finally, the most common penalties were solitary confinement or segregation and loss of good-time credit. Tables and description of methodology.