Following the Las Vegas shooting in October 2017 and the Stoneman Douglas High School shooting in February 2018, President Donald Trump and the DoJ sought ways to ban bump stocks, devices that can be used to make semi-automatic weapons fire as fully automatic ones as used in both shootings. Initially, the DoJ believed it had to wait for Congress to pass the appropriate legislation to ban the sale and possession of bump stocks. However, by March 2018, the DoJ introduced proposed revised regulations on gun control that incorporated bump stocks under the definition of machine guns, which would make them banned devices, as Congress had not yet taken any action. After a period of public review, the DoJ implemented the proposed ban starting on December 18, 2018, giving owners of bump stocks the option to either destroy them or turn them into authorities within 90 days, after which the ban would be in full effect (on March 26, 2019). Pro-gun groups immediately sought to challenge the order, but could not get the Supreme Court to put the ban on hold while the litigation was ongoing. In the following week, the Supreme Court refused to exempt the litigants in the legal challenge from the DoJ's order after this was raised as a separate challenge.