AbstractThe association between previous convictions and perpetrating homicide has been previously described but little is known about the characteristics of homicide offenders without previous convictions. By utilizing the unique database on homicide offenders held by the National Confidential Inquiry into Suicide and Safety in Mental Health, this study aimed to describe the sample of homicide perpetrators in England and Wales who have committed homicide as their first offense based on their sociodemographic and clinical characteristics. Compared with those with previous convictions, homicide offenders without previous convictions were more likely to be female and a member of an ethnic minority group. More of those without previous convictions belonged to the youngest (<25) and oldest (>55) age groups and were more likely to kill somebody family member or a spouse. Schizophrenia and other delusional disorders as well as affective disorders were more prevalent in those without previous convictions as were mental illness/insanity as a circumstance in homicide, but those without previous convictions were less likely to have been in previous contact with mental health services. There are clear sociodemographic and clinical differences between homicide perpetrators with and without previous convictions. Implications of these findings are discussed.