Gun control advocates and gun rights advocates have referred to at least some of the features outlined in assault weapons bans as "cosmetic". The NRA Institute for Legislative Action and the Violence Policy Center both used the term in 2004 when the federal ban expired. In May 2012, the Law Center to Prevent Gun Violence said, "the inclusion in the list of features that were purely cosmetic in nature created a loophole that allowed manufacturers to successfully circumvent the law by making minor modifications to the weapons they already produced." Some reporters used the term in stories after the 2012 shootings in Aurora, Colorado and at Sandy Hook Elementary School.