Recidivism can be calculated by year of conviction or discharge. In this context, re-offenders are persons who commit an offence in the three years following a conviction or release from a custodial sentence and who are subsequently reconvicted. A record is also made of the special case of persons who are not only reconvicted after discharge from a custodial sentence but also re-imprisoned.
The figures for adult recidivism concern only Swiss nationals; recividism rates for juveniles cover both Swiss and foreign nationals.
Among adults, the previous conviction and the recidivist conviction must always be due to a felony or misdemeanour. Among juveniles, the convictions can also be made solely on the basis of a contravention (less serious offences).
For this reason, the recidivism rates of juveniles and adults cannot be compared with one another.