People on here are saying no crime has been committed but the parents have alleged that ***ually explicit photographs were first sent when the subject was 17 years old and that is definitely illegal.
The police have not said that a crime hasn't been committed but have stated they have no evidence that a crime has been committed.
This implies that the burden of proof rests with the parents if they want to progress their allegations to a criminal case.
They will have to provide clear evidence but so far have either failed or neglected to do so.