US mass shooters exploited gaps, errors in background checks
TEXAS (AP) — Most mass shooters in the U.S. acquired the weapons they used legally because there was nothing in their backgrounds to disqualify them, according to James Alan Fox, a criminologist with Northeastern University who has studied mass shootings for decades.
But in several attacks in recent years gunmen acquired weapons as a result of mistakes, lack of follow-through or gaps in federal and state law.