homicide (n.)

"the killing of another person," early 13c., from Old French homicide, from Latin homicidium "manslaughter," from homo "man" (see homunculus) + -cidium "act of killing," from caedere "to kill, to cut down" (from PIE root *kae-id- "to strike").

The meaning "person who kills another" (late 14c.) also is from French (homicide), from Latin homicida "a murderer," from homo + -cida "killer." Identical in French and English, the two words differ in Latin and in other languages (for example, Spanish homicida/homicidio).