Assassination Ban
Executive Order from Gerald Ford.
"The assassination ban was put into place after the issuance of the 1975 Church Committee Interim Report which summed up the Committee’s investigation of, among other things, US-backed assassination plots against foreign leaders. The report concluded that the CIA had attempted to assassinate the leaders of Cuba and the Congo, and that it had aided assassination plots in the Dominican Republic, Chile, and Vietnam. Noting that “[a]dministrations change, CIA directors change, and someday in the future what was tried in the past may once again become a temptation,” the report recommended that Congress ban assassination. Concerned that Congress might do so, President Ford issued Executive Order 11905 which included this language: “No employee of the United States Government shall engage in, or conspire to engage in, political assassination.” Subsequent orders by Presidents Carter and Reagan reaffirmed the ban, albeit with modifications. The current version of the ban, in Executive Order 12333, states: “No person employed by or acting on behalf of the United States Government shall engage in, or conspire to engage in, assassination.”"
https://www.justsecurity.org/27407/assassination-ban-targeted-killings/