My question involves criminal law for the state of: USA (no state in particular)
This occurred around 5 years ago.
Someone I know was 19 at the time. He interacted sexually with someone online who claimed to be 14 and from the US. He asked if she wanted to see him masturbate and she said yes. He did, under the impression that he was not coercing anyone(nor going against anyone's autonomy) and that what he was doing was not self-evidently harmful. Some time later, he read up on such things and came to know of the concept of age of consent and the concept of minors. What he did was not illegal in his country of residence(he asked local lawyers since he does not reside in the US nor is he a US citizen), but he was just wondering if anything could come of this legally. From what I read, on the federal level, any non-capital offense has a statute of limitations of 5 years. Is there any way the statute of limitations could go longer due to some exception? Could US jurisdiction be claimed in the first place?
After this person found out about the law and the social derision to such actions, he felt bad and never did anything again. It's just that he didn't know about such laws and what he did wasn't evidently wrong to him at the time. Had he just that piece of knowledge, he most definitely wouldn't have done anything.

