perpetrator

[pur-pi-trey-ter] /ˈpɜr pɪˌtreɪ tər/

noun

a person who perpetrates, or commits, an illegal, criminal, or evil act:

The perpetrators of this heinous crime must be found and punished to the fullest extent of the law.

Examples from the web for perpetrator

Identifying the perpetrator of cyber-attacks can be impossible.
The guilty knowledge test focuses its questions on knowledge that only a perpetrator would have.
After a number of false leads peter out the perpetrator is discovered when he makes a slip.
There is an indication that a police officer may be the perpetrator.
The perpetrator of the crime was discharged from service.
The perpetrator remains unknown.
No finger of blame can be pointed at any perpetrator.
Reading it is like happening upon a street crime and entering the perpetrator's mind.
Lastly, a confession proves guilt if the accurate facts it contains are knowable only to a perpetrator.
But the toxin is not the ultimate perpetrator of tetanus.

Word Origin and History for perpetrator

literally "the one who did it" (in English usually an evil act), 1560s, from Late Latin perpetrator, agent noun 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).