S: (n) murderer, liquidator, manslayer (a criminal who commits homicide (who performs the unlawful premeditated killing of another human being))
S: (n) assassin, assassinator, bravo (a murderer (especially one who kills a prominent political figure) who kills by a surprise attack and often is hired to do the deed) "his assassins were hunted down like animals"; "assassinators of kings and emperors"