In October 2017, after the Las Vegas shooting, Cicilline introduced a bill to ban bump stocks. After the Marjory Stoneman Douglas High School shooting, he introduced the Assault Weapons Ban Act of 2018. The bill would ban 205 specific fireams, such as the AR-15 and the AK-47, outright. Cicilline was also among the members of Congress who supported the National School Walkout, and met with protesters at the U.S. Capitol.