In 1994, President Bill Clinton signed a 10-year ban on so-called assault weapons, which expired in 2004 and was not renewed. Democrats claimed that the ban reduced mass shootings during those 10 years, and they contend that the new bill, sponsored by Representative David Cicilline (D-R.I.), would reduce mass shootings again.

The bill proposes to ban the sale, manufacture, transfer, possession, or importation of many semi-automatic weapons. It also would criminalize "large-capacity ammunition feeding devices," defined as detachable magazines capable of holding more than 15 rounds. Current owners of "assault weapons" would be grandfathered in, and would not have to give up their firearms, but new sales and manufacture of such items, except for government use, would be prohibited.