Who made the highly publicized finding that in prison programs almost nothing works?

The highly publicized finding that "almost nothing works" in prison programs was popularized by criminologist Martinson in his 1974 essay titled "What Works? Questions and Answers About Prison Reform." His review of various rehabilitation programs suggested that most had little to no effect on recidivism rates, leading to significant debate and further research on the effectiveness of correctional interventions. This conclusion sparked a reevaluation of rehabilitation strategies in the criminal justice system.