perp
UK[pɜːp]US[pɜːrp]
n
A perpetrator of a crime or offense.
Etymology
The word 'perp' is a 20th-century American slang truncation of the noun 'perpetrator.' 'Perpetrator' itself entered English in the mid-16th century from Late Latin perpetrator, meaning 'one who carries out or performs,' derived from the verb perpetrare ('to accomplish, perform'). This Latin verb is a compound of per- ('thoroughly') and patrare ('to bring about'), which is related to pater ('father'), suggesting a sense of bringing something to completion. In modern police and legal jargon, 'perp' has become a standard, informal term specifically for a person who commits a crime, stripping away the broader, more neutral historical connotations of its parent word.
Analysis
This word is a modern English slang clipping, not formed from classical morphemes. It is a direct shortening of the noun "perpetrator."
Examples
The detective quickly identified the perp from the security footage.
The witness was asked to point out the perp in a police lineup.
In the report, the officer noted that the perp fled the scene on foot.