Items were chosen based on a comprehensive review of the literature and input from experienced forensic clinicians. The HCR-20 includes variables which capture relevant past, present and future considerations and should be regarded as an important first step in the risk assessment process. The manual provides information about how and when to conduct violence risk assessments, research on which the basic risk factors are based and key questions to address when making judgements about risk.
Violence is defined as 'actual, attempted, or threatened harm to a person or persons'. The professional who completes the HCR-20 Coding Sheet must first determine the presence or absence of each of the 20 risk factors according to three levels of certainty (i.e. Absent, Possibly Present, Definitely Present). In some settings, responsibility for the assessment may be divided among several different professionals.
The 20 Items are divided into three sections:
- 10 Historical Items (previous violence, age at first violent offence, family and vocational background etc.).
- Five Clinical Items (current symptomatology and psychosocial adjustment).
- Five Risk Management Items (release and treatment plan, necessary services and support).
Historical information serves as an anchor for risk assessments because there is a strong predictive link between past and future violent behaviour. Such information should be verified carefully, as historical considerations may modify analyses of clinical and situational factors. In some cases, it may be necessary to contact friends or family members of the individual for verification of past events. The five clinical variables can be assessed at regular intervals so that risk level may be modified accordingly. The risk management items focus on predicting how individuals will adjust to future circumstances, and this is directly related to the context within which the individual will be living.
The final judgement regarding the risk for future violence (low, moderate, high) should be based on a careful analysis of the 20 risk factor items. Any statements of risk should take into consideration the base rate of violence in the particular population or setting (e.g. low, moderate or high risk relative to other correctional inmates).