A sex offender is a person who has committed a sex crime. What constitutes a sex crime differs Other serious offenses are sexual assault, statutory rape, bestiality, child sexual abuse, female . being 17 in New York, meaning that, had he been convicted, John Walsh himself could be required to register as a sex offender. Sexual Offense Law and Legal Definition. Sodomy is defined similarly to rape, except that it involves deviate sexual conduct, as opposed to intercourse. Sexual abuse involves similar elements of force or lack of consent, but involves sexual contact, rather than intercourse or deviate sexual acts.