A ten-year research project to understand and treat criminality has led to the development of a new test of criminal thinking, Survey of Thoughts, Feelings, and Behaviors (STFB) and a new understanding of criminality as six sets of angry distress-rejecting attitudes and behaviors on the part of offenders-behaviors that put them into conflict with society and get them in trouble with the law. This new understanding of criminality suggested the development of six different treatment programs, one for each of these six separate components of criminality, and these treatment programs were delivered in six day-long (i.e., four-and-a-half hour) large-group treatment workshops. None of those inmates who were assigned to and received three or more of these treatment workshops recidivated (i.e., relapsed into crime) within the two years following release from prison; in contrast to a control group of inmates who received none of these criminality workshops, half of whom were back in prison within two years of being released. It was concluded that this particular approach to understanding and treating criminality would seem to warrant further investigation and application.