The assault weapon used in the worst mass shooting in U.S. history was manufactured by Sig Sauer, according to law enforcement. Sig Sauer is an NRA corporate donor and sponsors the NRA News series “Defending Our America.”

During the early morning hours of June 12, a gunman attacked a gay nightclub in Orlando, FL, killing 49 people and wounding 53 others before he was killed by law enforcement. According to law enforcement, the gunman purchased a Sig Sauer MCX assault weapon on June 4 that he used in the attack.

Sig Sauer is a “James Madison” level donor to the NRA, meaning it has contributed between $25,000 and $49,999 to the gun organization. Sig Sauer is also the sponsor of the NRA News series “Defending Our America.”

On its website, Sig Sauer markets the MCX as: “Built from the ground up to be silenced, light and short”:

The gun is also described by Sig Sauer as “battle-proven”:

A Sig Sauer video demonstrating the weapon’s rapid-fire capabilities notes, “The Sig MCX eclipses everything that’s come before it. It’s the start of a new era”:

The weapon is sold in a semi-automatic version to civilians and also marketed to special forces with a selective-fire version. According to a review of the MCX on the website The Truth About Guns, “When it comes to getting shots on multiple targets quickly -- especially when shooting with a silencer attached -- an MCX-wielding rifleman will have a distinct advantage.”