Risk assessment is important in the social (1), political (2), clinical (3) and ethical (4) domain. It has several goals:

• It can be used to gain insight into heterogeneous groups of offenders.
• It can be used to prevent recidivism.
• It can be used to provide guidelines for treatment.
• It can be used to structure discussions among professionals (e.g. judges, practitioners).
• It can be used to protect the rights of the person and protect society.

The risk depends on the situation and the risk assessment is never certain. The quality of risk assessment depends on the available information regarding the individual (1), the instrument that is used (2) and the professional (3).

Risk assessment refers to assessing the risk of future violent or non-violent behaviour. It estimates the likelihood that someone will exhibit a certain behaviour (e.g. violence) in the near or distant future. The purpose is to increase the ability to detect true positive and true negative cases and keep the false positives and false negatives to a minimum. The base rate refers to the prior probabilities in an outcome domain (e.g. recidivism rate in sex offenders).

Risk assessment can be used to gain insight into heterogeneous groups of offenders through gaining information regarding risk factors that are related to recidivism. Denial of the crime and the severity of the crime is not predictive of sexual recidivism. Impulsive, anti-social tendencies and sexual deviance and preoccupation are predictive of sexual recidivism.

The structured professional approach uses systematic collection (1), reviewing (2), combining (3), weighing (4) and integrating (5) information on risk factors. Treatment aimed at reducing violent recidivism should focus on reducing risk factors and reinforcing protective factors.

There are several approaches to risk assessment:

1. Unstructured clinical judgement
   In this method, the risk factors are determined using experience and knowledge of the expert. The decision making is based on personal choice and is unstructured. It is more flexible and tuned to the individual. This method has low interrater reliability and low predictive value, making this method suboptimal.
2. Actuarial risk assessment
   In this method, the risk factors are determined using a fixed list of risk factors. This list is based on empirical research. The decision making is based on the sum score of the risk factors. The estimation of risk is based on a comparison with norm groups.
3. Structured clinical judgement
   In this method, the risk factors are determined using a fixed list of risk factors but there is the possibility to add risk factors based on clinical experience. The decision making is based on the presence of a risk factor (1), clinical experience (2) and clinical insight (3). This method does not employ comparison with norm groups.

In the structured clinical judgement method, only the presence of a risk factor matters. The absence of a risk factor is of lesser importance. Risk classification is either low, moderate or high risk.

The choice of test instrument for supervision and risk assessment depends on what you want to assess (1), the context (2) and the predictive validity of the instrument (3). Static risk factors are historical and unchangeable. The scoring is reliable and easy. It has a good predictive validity. Dynamic risk factors can be stable or acute. Stable dynamic risk factors can change but the change is slow (e.g. personality traits). Acute dynamic risk factors can change quickly (e.g. relationship status). Protective factors exhibit a negative relationship with recidivism.

Common mistakes in practice are not using risk assessment (1), not using a risk assessment tool (2), using the wrong risk assessment tool (3) and using the risk assessment tool in the wrong way (4).

The HCR-20 V3 is used for the assessment of risk of future violence. It consists of 20 items split over three domains. The historical subscale  (1), the clinical subscale (2) and the risk management subscale (3). It has a good interrater reliability and strong predictive validity. It contains several steps:

1. Case information
   This step includes gathering information about the individual of interest.
2. Presence of risk factors
   This step includes describing what risk factors are present in the individual of interest.
3. Relevance of risk factors
   This step includes describing the relevance of risk factors. It also includes describing which risk factors are most important to consider when making plans about monitoring (1), treatment (2), supervision (3) or victim safety planning (4).
4. Risk formulation
   This step includes formulating a conceptual meaningful framework of risk factors.
5. Risk scenarios
   This step includes a formulation of future scenarios.
6. Management strategies
   This step includes translating the information into a risk management plan.
7. Conclusory opinions
   This step includes drawing conclusions about the individual for risk of future violence.

Risk management plans consist of several activities:

1. Monitoring / surveillance
   The goal of monitoring is to evaluate changes in risk over time. It focuses on surveillance and not on control or restriction of personal liberties.
2. Treatment
   The goal of treatment is to improve deficits in the individual’s psychosocial adjustment or functioning.
3. Supervision
   The goal of supervision is to make it more difficult for the individual to engage in future violence. This includes a restriction of the person’s rights and freedoms.
4. Victim safety planning
   The goal of victim safety planning is improving a potential victim’s security resources.

Risk factors for the development of sexual offending are adverse family environments (1), lacking nurturance and guidance (2) and beliefs that permit non-consensual sex (3). Persistent sex offenders may be characterized by a negative family background (1), problems forming affectionate bonds with friends and lovers (2) and attitudes tolerant of sexual assault (3). Problems with self-regulation (1), psychopathy (2), a history of non-violent crime (3) and history of non-sexual crime (4) are predictors of recidivism.

The risk-need responsivity model is a risk model which states that the focus of treatment should be on rehabilitation (i.e. avoiding additional damage to society). The well-being and general functioning of the patient are of secondary importance.

The risk principle states that people who are at higher risk for recidivism should receive more intensive treatment (e.g. patient with medium risk should receive forensic outpatient treatment). Treatment that is not related to the level of risk (e.g. low-risk patient receives intensive treatment) is associated with higher levels of recidivism. This is due to the influence of antisocial peers present in these settings (1), the impact of this treatment on protective factors (2) and the manipulation by high-risk groups (3).

The need principle indicates what the focus of treatment and supervision should be. The treatment should be focused on criminogenic factors (i.e. factors that directly relate to the risk of recidivism). These factors can only be assessed using risk assessment tools. The outcome of risk assessment should include advice regarding the criminogenic needs.

The responsivity need states that the treatment programme should be tailored to the characteristics of the offender (e.g. learning style and motivation). It is thus necessary to take the (dis)abilities of the offender into account (e.g. low affect; low IQ; psychiatric disorders). Psychiatric disorders are often a responsivity factor and not a risk factor.