"Gettingyour lifebackontrackaftercommittingacrime ischallenging. During probation supervision, probation officers build andmaintain intensive and often long-term partnerships with probationers to prevent relapse into delinquent behavior. This thesis reveals an important success factor of probation supervision. Large groups of probationers and probation officers were followed for four years. A good and mutual cooperation between probationer and probation officer, the working alliance, is crucial. There is a strong association between the working alliance factor trust and relapse into criminal behavior. This implicates that during supervision themost important question for both probationer and probation officer is: ‘Can we trust each other?’"