Although the vast majority of mentally ill individuals are non-violent, some evidence has suggested that mental illness or mental health symptoms are nearly universal among school shooters. A 2002 report by the US Secret Service and US Department of Education found evidence that a majority of school shooters displayed evidence of mental health symptoms, often undiagnosed or untreated. Criminologists Fox and DeLateur note that mental illness is only part of the issue, however, and mass shooters tend to externalize their problems, blaming others and are unlikely to seek psychiatric help, even if available. According to an article written on gun violence and mental illness, the existence of violence as an outlet for the mentally ill is quite prominent in some instances (Swanson et al., 2015). The article lists from a study that 12% of people with serious mental illness had committed minor or serious violence within the last year, compared to 2% of people without illness committing those same acts. Other scholars have concluded that mass murderers display a common constellation of chronic mental health symptoms, chronic anger or antisocial traits, and a tendency to blame others for problems. However, they note that attempting to "profile" school shooters with such a constellation of traits will likely result in many false positives as many individuals with such a profile do not engage in violent behaviors.