My stepdaughter had sexual relations at the age of 14 with a boy who was 18 at the time. She is now just turned 17 and he is 21 years. Could we still press charges on him for stagetory rape?

Firstly, it is statutory rape. Secondly, it all depends on where you live. Every location in the world has a different Age of Consent.

It may depend on your state. Which state do you live in?

Florida

j_9 is absolutely correct. Here is one reference to give you an idea.
I think the best bet is to contact the State's Attorney (or equivalent in your area). He or she would have to file the charges if applicable.

Florida Statute of Limitations for Crimes Against Children | Sexlaws.org

Based on the information in the link smear provided, until your stepdaughter turns 18 there is no limit on how long you can wait to prosecute.

So your best bet is to visit your local prosecutor or district attorney and discuss the prosecution with them. They can tell you whether you have a strong enough case or not.

Here is what I found for the state of Florida

A person who commits sexual battery upon a person 12 or over, commits a 1st degree felony when:

* The victim is physically helpless to resist;
* When the offender coerces with threats to use force or violence, or retaliate;
* When the offender administers an intoxicating substance that incapacitates the victim; etc.

And here is the statute of limitations

§775.15 (2)(a) – Prosecution for a
felony of the 1st degree --
within 4 yrs.

When did you find out about this? Have you known that she had sex since it happened? I don't think it makes a difference in the eyes of the law - I am actually just curious.

The answer is no.

The State is not going to prosecute him because you can't prove that they had sex.

It costs taxpayers a lot of money to prosecute criminals. Young lovers, who's parents did not know they had a sexually active 13 year old for 4 years are not criminals, they are just kids with inattentive parents.

Sorry for samrtnsexa who does not understand the law, yes of course you can, and often just the girl confessing is enough. And a adult who has sex with a child is a seroius criminal and this law helps stop other adults from abusing children. So yes they can often convict these molestors.