On Aug. 3, shoppers at a Walmart and adjacent shopping center in El Paso recounted the moment an armed gunman opened fire, leaving multiple dead and wounded. (Video: Raul Hernández/The Washington Post)

The recent gun violence in or near Walmart stores, in El Paso on Saturday and in Mississippi days before, has drawn attention to the company’s complicated history with gun sales.

Firearms have long made up a key part of Walmart’s business. In addition to being the world’s largest retailer, Walmart is often referred to as the world’s largest gun retailer.