In the first update to its use-of-force policy after a string of killings by police in recent years, the Justice Department has ordered federal agents to step in to “prevent or stop” excessive force by other members of law enforcement, The Washington Post reports. The policy change, the first update to its use-of-force policy since 2004, was spelled out in a memo from Attorney General Merrick Garland that was sent to federal law-enforcement agents. “Officers will be trained in, and must recognize and act upon, the affirmative duty to intervene to prevent or stop, as appropriate, any officer from engaging in excessive force or any other use of force that violates the Constitution, other federal laws, or Department policies on the reasonable use of force,” the memo reads, according to the Post. The updated policy, which also mandates federal law-enforcement officers to “act upon” any kind of medical emergency they see, is due to take effect on July 19. The policy change comes after several protests in recent years over police killings, including the 2020 murder of George Floyd, whose death was initially deemed a “medical incident” by police before it was later determined to be a homicide at the hands of officers.