The violent and senseless death of 11-year-old Luke Batty in Victoria has not only drawn attention to the serious problem of family violence but has also raised questions about the role that undiagnosed or untreated mental illness may have played in his father's behaviour. The relationship between violence and mental illness is a vexed and contentious issue. The vast majority of people experiencing mental illness are not violent. However, those with a serious mental illness have increased rates of violence, including family violence, when compared to people who do not have a mental illness.