The word perpetrate was first used in UK parliamentary records from the 1470s, and it was borrowed directly from Latin perpetratus, meaning "accomplished". That comes from the verb perpetrare, or "carry through", which is composed out of per, meaning "through" in this context, and patrare, which is best translated as "to bring into existence". Per is reconstructed as coming from a Proto-Indo-European root that sounded very similar, and patrare traces to the Latin word for "father", pater, because fathers definitely are people who bring things into existence. Through Proto-Italic, that derives from Proto-Indo-European phter, also "father". Perp as an abbreviation for "perpetrator" emerged in 1968, and usage of the word perpetrator has skyrocketed since the 1960s.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.