Ok so if a girl at 14 engages in sexual acts with a guy who she started talking to when he was was 19, but is now 20 and there is WRITTEN PROOF and the girl confesses and ADMITS that she told him she was 17, what happens? If the mom doesn't want to press charges, is that enough? What's best and worst case scenario for the guy?

Below are the laws that would apply in this situation. They are found under chapter 14 (Sexual offenses) of the NJ criminal code. (Specifically, see 2C:14-5 in bold and also 2C:14-2 in bold toward the bottom of the page)

2C:14-5. Provisions generally applicable to Chapter 14

a. The prosecutor shall not be required to offer proof that the victim resisted, or resisted to the utmost, or reasonably resisted the sexual assault in any offense proscribed by this chapter.

b. No actor shall be presumed to be incapable of committing a crime under this chapter because of age or impotency or marriage to the victim.

c. It shall be no defense to a prosecution for a crime under this chapter that the actor believed the victim to be above the age stated for the offense, even if such a mistaken belief was reasonable.

2C:14-2. Sexual assault.

a. An actor is guilty of aggravated sexual assault if he commits an act of sexual penetration with another person under any one of the following circumstances:

(1) The victim is less than 13 years old;

(2) The victim is at least 13 but less than 16 years old; and

(a) The actor is related to the victim by blood or affinity to the third degree, or

(b) The actor has supervisory or disciplinary power over the victim by virtue of the actor's legal, professional, or occupational status, or

(c) The actor is a resource family parent, a guardian, or stands in loco parentis within the household;

(3) The act is committed during the commission, or attempted commission, whether alone or with one or more other persons, of robbery, kidnapping, homicide, aggravated assault on another, burglary, arson or criminal escape;

(4) The actor is armed with a weapon or any object fashioned in such a manner as to lead the victim to reasonably believe it to be a weapon and threatens by word or gesture to use the weapon or object;

(5) The actor is aided or abetted by one or more other persons and the actor uses physical force or coercion;

(6) The actor uses physical force or coercion and severe personal injury is sustained by the victim;

(7) The victim is one whom the actor knew or should have known was physically helpless, mentally defective or mentally incapacitated.

Aggravated sexual assault is a crime of the first degree.

b. An actor is guilty of sexual assault if he commits an act of sexual contact with a victim who is less than 13 years old and the actor is at least four years older than the victim.

c. An actor is guilty of sexual assault if he commits an act of sexual penetration with another person under any one of the following circumstances:

(1) The actor uses physical force or coercion, but the victim does not sustain severe personal injury;

(2) The victim is on probation or parole, or is detained in a hospital, prison or other institution and the actor has supervisory or disciplinary power over the victim by virtue of the actor's legal, professional or occupational status;

(3) The victim is at least 16 but less than 18 years old and:

(a) The actor is related to the victim by blood or affinity to the third degree; or

(b) The actor has supervisory or disciplinary power of any nature or in any capacity over the victim; or

(c) The actor is a resource family parent, a guardian, or stands in loco parentis within the household;

(4) The victim is at least 13 but less than 16 years old and the actor is at least four years older than the victim.

Sexual assault is a crime of the second degree.