In the majority of mass shootings the suspect is found to have had mental health issues, to the point where legally they should not have been able to purchase a firearm. And yet, more often than not, the guns used to commit these shootings were legally purchased by the suspect.
According to an info-graphic from FaceTheFactsUSA, “Between 1998 and 2009, 95 million potential buyers’ records were scanned.” Of that, roughly 1.3 million were denied firearms because of failure to pass background checks. But of that 1.3 million, just 28,637 were denied on the basis of mental health issues. This means that, “Just 0.03 percent (of gun purchases) were denied a gun over mental illness concerns.”
According to FaceTheFactsUSA, a major obstacle the National Instant Criminal Background Check System (NICS) faces in preventing the mentally ill from purchasing firearms is a lack of a substantial database. Though the various mass shootings over the years have caused an increase in background checks and file sharing over the years, “About half the states have not supplied their records (to the NCIS).”