At attacks on federal government that happened over 13-year period. in that study, just under half had symptoms of mental illness. half did not. and so regardless whether someone has a mental illness or not, it really is investigating the behaviors, their life factor, situational factors. ainsley: is there one that really stood out. >> in this report? ainsley: um-huh. >> one of the biggest things that i saw. most of the findings support what we already know in terms of the stressors concerning behaviors. one of the biggest things we saw in terms of the age group, sometimes kind of misconceptio...