Definition - What does Perpetrator mean?
A perpetrator is a person who committed a crime. The word is commonly used by members of law enforcement to distinguish people who committed crimes from people who didn't. The term is also commonly used in prisons.
"Perp" is an abbreviated version of this word that is also used frequently.
Justipedia explains Perpetrator
The word "perpetrator" is more specific than the word "criminal"; it is used to distinguish convicted criminals from suspected criminals.
Suspected criminals that are set to face trials are known as either "alleged criminals," or "defendants." A defendant has an opportunity to defend their case before a court of law to prove their innocence of the accused crime. All defendants are innocent until proven guilty.