I don’t see the big deal about letting minors consent to sex. I remember being 13 and knowing which things I wanted and which I didn’t. Even at 9 years old, I held meaningful opinions about things that were happening to me: “Where would you rather go to dinner?” “Where would you rather go to school?” “We think you should have braces to straighten your teeth, how do you feel about that?”
I knew what sex was, and I knew what physical discomfort was. If someone was physically doing something to me that I didn’t like, I would have realized it immediately. And so would every one of my peers.
Problem: A 20-year-old man has sex with a 13-year-old girl. Was it consensual?
Solution: Let the girl know that her answer is entirely private and that no harm will come to her from answering or testifying in court. Then ask her if the sex was consensual. If she says yes, don’t waste any more taxpayer money on the case.
Oh, but you suspect the man may have threatened her to keep quiet. So handle it exactly like any other case of suspected threats toward witnesses, don’t just assume that it happened because you don’t trust minors.