Many years ago there was a similar incident in Pennsylvania, young female victim, older neighbor, not relative, girl maybe 12 or 13, boy not much older.
Girl disappears, they find her body a few days later.
Neighbor kid is arrested, all sorts of hearings and tests to determine if he's competent to stand trial, if he's going to be tried as an adult...
He's judged competent, is tried as an adult.
Defense is painting a pretty effective involuntary manslaughter defense , but it all sort of falls apart when the kid's on the stand and says something very much along the lines "she was a slut and she deserved it."
Supposedly he actually had some sympathy from the jury before that. After that they came back with a second degree murder conviction.