Risk assessment in prisons is used mainly for two purposes, to differentiate prisoners’ placement in the prison system (i.e. higher or lower security) and to take preventive measures on the individual level. Tools might differ depending on if they are supposed to be used for assessing risks during the prison stay, or if the purpose is to assess risk for recidivism. However, most assessment tools contain the same four dimensions: criminal history, persistent anti-social lifestyle, anti-social personality, and drug/mental health issues. Factors might be added depending on the crimes committed, for example sexual offences or partner violence. The needs assessment is mainly used to allocate resources to the client, for example treatment programmes, education or medical treatment, but can also be used for pre-release measures planning.