The purpose of the Hare P–SCAN instrument is to help individuals in the mental health and corrections environments systematize what many already do: form impressions and draw conclusions on the basis of their knowledge and their experience about patients, offenders, and suspects.

The P–SCAN assessment does not provide a clinical diagnosis or narrative assessment. Instead, the administrator uses his or her knowledge of the individual, along with all other information available, to rate the person's tendency toward psychopathic behaviours. The checklist items depict relatively specific behaviours and low-level inferences about individuals. Items represent the three key facets of psychopathy: interpersonal, affective, and lifestyle.