As the US has been facing an increase in mass-shootings, looking at how juries understand mental illness as it relates to these crimes is becoming increasingly important. This study explores public opinion of the insanity defense and the public's view of mental illness in three high -profile crimes. The review of the literature indicates that there is significant misconception amongst the public regarding mental illness as well as the insanity defense. This is has major implications for the outcomes of jury trials as prospective jurors are selected from the public who may have preconceived notions of mental illness and the insanity defense. I hope you enjoy this study.