offender

accomplice, principal

desperado, outlaw

convict, jailbird

perp, perpetrator

evildoer, gallows bird, misdoer, misfeasor, sinner, transgressor, trespasser, villain, wrongdoer

blackhander, gangster, hoodlum, hooligan, mobster, racketeer, thug

enforcer, gun, gunman, hit man, triggerman

backslider, recidivist, relapser, repeater

accused, arrestee, defendant, detainee, fish, suspect