The Collaborative International Dictionary of English v.0.48:

law-breaking \law-breaking\ n.
   1. an act punishable by law; usually considered an evil act.

   Syn: crime.
        [WordNet 1.5] lawbreaker

The Collaborative International Dictionary of English v.0.48:

lawbreaker \law"break`er\, law-breaker \law"-break`er\, n.
   One who disobeys the law; someone who violates the law; a
   criminal.

   Syn: violator, lawbreaker, law breaker, perpetrator.
        [1913 Webster + WordNet 1.5] -- Law"break`ing, n. & a.
        [1913 Webster]

WordNet (r) 3.0 (2006):

law-breaking
    n 1: (criminal law) an act punishable by law; usually considered
         an evil act; "a long record of crimes" [syn: crime,
         offense, criminal offense, criminal offence,
         offence, law-breaking]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "lawbreaking":
   breach of law, civil disobedience, contravention, crime,
   criminal tendency, criminality, criminosis, disobedience,
   evil courses, evildoing, feloniousness, frowardness, indiscipline,
   indocility, infraction, infringement, insubordination,
   intractability, lawlessness, malfeasance, malpractice,
   malversation, misconduct, misdemeanor, misdoing, misfeasance,
   misprision, misprision of treason, naughtiness, noncompliance,
   nonconformity, noncooperation, nonobedience, passive resistance,
   positive misprision, recusancy, sin, thou scarlet sin,
   transgression, trespass, trespassing, uncooperativeness,
   unduteousness, undutifulness, unsubmissiveness, vice, viciousness,
   violation, violation of law, waywardness, willful disobedience,
   wrong conduct, wrongdoing