As justice minister, Keenan oversaw the first national firearms amnesty since the 1996 Port Arthur massacre. It ran from July to September 2017, allowing people to hand in unregistered or unwanted firearms. The amnesty had been approved in March 2017 by the Firearms and Weapons Policy Working Group (FWPWG) to reduce the number of unregistered firearms in Australia that were being used in Islamic terrorist attacks.