Risks and determinants of firesetting behaviour: characteristics, psychiatric morbidity and recidivism

Firesetting has long captured the imagination of psychiatry and the public alike. The crime of arson has enormous potential for significant property damage and loss of life. Despite this, and the lengthy research history, arson remains one the least understood criminal behaviours in terms of the characteristics of the offenders and the development and maintenance of the behaviour. The dearth of knowledge about the unique characteristics of firesetters may be due to the lack of properly controlled studies using representative samples of firesetters. This research thesis sought to clarify the offending histories, and the psychological, psychiatric and social variables that may differentiate firesetters from other offenders. This information is important not only for forensic clinicians who assess and treat firesetters, but also for police and policy-makers who are charged with reducing the incidence of the crime. A robust case-linkage methodology was adopted, linking information contained in state-wide mental health and criminal records databases to compare patterns of criminality and psychiatric morbidity in firesetters, other offenders and community controls. The firesetting sample comprised the population of offenders who had been convicted of arson or arson-related crimes between 2000 and 2009. In addition, a subsample of the population was examined using information contained in court files. This thesis comprised three related empirical studies. The first study examined the demographic, criminological and clinical characteristics of firesetters and compared these with a random sample of non-firesetting offenders using information from court files. All firesetters who were convicted of arson between 2004 and 2009 (n = 207) were examined. In addition, the study sought to establish whether offenders with only arson (exclusive) in their offending histories differed from those who were versatile (firesetting and other offence types). The findings suggest that deliberate firesetters and other offenders are similar on key characteristics, with the exception of employment and educational achievement in which firesetters had lower levels, and the higher level of psychological distress reported by firesetters. When comparing exclusive firesetters with the other groups few differences emerged, including in the incidence of past firesetting. However, the more criminally versatile firesetters reported poor occupational outcomes, more contact with the criminal justice system and reported higher levels of psychological distress or diagnosis than even the versatile non-firesetting offenders. It was concluded that firesetters are mostly versatile offenders, and this pattern of offending is associated with greater levels of criminogenic need than exists among non-firesetting offenders. Firesetting is often reported to be associated with psychopathology, but frequently these conclusions are based on studies reliant on selective forensic psychiatric samples without the use of comparison groups. The second empirical study sought to compare the rates and types of mental illness, substance use disorders, personality pathology and psychiatric service usage of a population of convicted firesetters (n =1328), non-firesetting offenders (n = 421) and matched community members (n = 1328) to determine whether mental disorder was differentially associated with firesetting. While the majority of firesetters did not have any history of contact with psychiatric services or to have received diagnoses, they were significantly more likely to have been registered with psychiatric services compared with other offenders and community controls, and were more likely to have utilised a diverse range of public mental health services. Firesetters attracted psychiatric diagnoses more often than community controls and other offenders, particularly affective, substance use, and personality disorders. The third empirical study examined the rate of firesetting recidivism in a representative sample of firesetters before the courts (n = 1052), and examined whether the rates of firesetting recidivism differed between exclusive and versatile firesetters. Moving beyond description, the study then developed a model to predict reoffending, using factors that are available to police and mental health professionals. The rate of firesetting recidivism was very low (5.3%) compared with the rate of general recidivism (55.4%); the vast majority of firesetting recidivists were mixed (criminally versatile) offenders (91%). The study found that general criminality, firesetting history, and psychiatric disorder were associated with firesetting recidivism. However, the low base rate of firesetting recidivism precluded the development of a tool that could accurately identify individuals who were at increased or decreased risk of recidivistic firesetting. Taken together, this research suggests that firesetters are versatile offenders who share many characteristics with non-firesetting offenders. However, congruent with past research, firesetters do exhibit greater levels of psychiatric impairment, socio-demographic disadvantage and tend to have extensive criminal careers. Implications of the results for forensic clinicians, mental health workers, police and policy-makers are considered