Legal Question in Civil Litigation in Kentucky

The crime could possibly still be prosecuted, depending on whether it was a felony.

I wonder, though, if you're correct that a crime was committed. There are often misconceptions concerning what the "age of consent" is in Kentucky, and who can be prosecuted for what. Take a look at the two applicable statutes, regarding statutory rape:

KRS 510.050 Rape in the second degree.

(1) A person is guilty of rape in the second degree when:

(a) Being eighteen (18) years old or more, he engages in sexual intercourse with another person less than fourteen (14) years old;

or

KRS 510.060 Rape in the third degree.

(1) A person is guilty of rape in the third degree when:

(b) Being twenty-one (21) years old or more, he or she engages in sexual intercourse with another person less than sixteen (16) years old;

Both are felonies.

On the other hand, here's a Class A misdemeanor, which is going to have a 1 year statute of limitations (which means it cannot be prosecuted, because if your child was 15 at the time, and is now 18, then it's passed the statute of limitations):

KRS 510.120 Sexual abuse in the second degree.

(1) A person is guilty of sexual abuse in the second degree when:

(b) He or she is at least eighteen (18) years old but less than twenty-one (21) years old and subjects another person who is less than sixteen (16) years old to sexual contact;

If your child was under 16 at the time, and the perpetrator was 21 or older, then you can still prosecute. Or if your child was under 14 at the time, you can still prosecute. (I didn't include the statute for rape in the first degree, which includes a child under 12.)