Perpetrators of mass shootings are far more likely to suffer from serious mental illness than the general public. This is especially true of people who commit indiscriminate mass shootings in which an attacker wantonly kills people in a public setting like a school, park, or church. Per a 2020 paper in the journal Criminology & Public Policy, 35% of the people who committed indiscriminate mass shootings from 1976 to 2018 had paranoid schizophrenia, and 60% of the shooters "had been either diagnosed with a mental disorder or demonstrated signs of serious mental illness prior to the attack." In comparison, less than 1% of the U.S. general population have schizophrenia or a related disorder, and 4.6% of noninstitutionalized U.S. adults have a serious mental illness.