1560s, "one who commits or has committed," literally "the one who did it" (in English usually an evil act), from Late Latin perpetrator, agent noun from past-participle stem of perpetrare "to perform, to accomplish" (see perpetrate). Fem. forms are perpetratress (1811, of Nero's poisoner Locusta); perpetratrix (1862, in reference to Charlotte Corday).

1940s American English police jargon shortening of perpetrator (as in perp walk).

"state of mind accompanying an act which condemns the perpetrator to criminal punishment," Latin, literally "guilty mind;" from mens "mind," from PIE root *men- (1) "to think."