In over 80 years of randomized experiments on crime, surprises and discoveries have repeatedly shown the failure of theories without evidence. They have also demonstrated the superiority of new approaches that have helped to reduce crime. RCTs have, for example, found higher death rates caused by well-intentioned programs for juvenile delinquency and domestic violence. But they have also found strong crime reduction effects for hot spots policing and restorative justice. The complexity of criminal behaviour and of government programs requires a “Triple-T” of systematic evidence in Targeting different kinds of crime and criminals for randomized Testing of specific programs based on Tracking service delivery with independent measures to insure test validity.