John Culhane, writing in SLATE, describes the problem:
Like any major public health problem, stemming gun violence will require multiple, overlapping strategies. Let me offer another one, overlooked until now, but potentially a dynamo: Repeal the little-known, but pernicious, Protection of Lawful Commerce in Arms Act. In other words, reopen the door to lawsuits against gun sellers for wrongful conduct in the design and marketing of their weapons.
In 2005, at a high point of the NRA’s control of the national agenda on guns, Congress passed this breathtakingly broad and virtually unprecedented law. Overriding states’ power to regulate harmful conduct within their borders, the PLCAA eliminated most tort claims anyone might bring against the manufacturers and other sellers of guns.