Probably the high end, although the exact facts will make a difference because these types of crimes can be charged in multiple ways and, in addition, they often will be separate crimes so the sentences can be run consecutively or "stacked" so that all of one sentence has to be completed before the next starts.
DNA is not required and, in these type of cases, is often not available.
It doesn't hurt the case that he was a minor but it may change the charge. Again, it depends on the exact facts.
I have handled a number of these types of cases. There is no question in my mind that if it was my daughter I'd report it, but that is a personal decision and what I would do shouldn't be the dispositive consideration
for you. Likely if there are other children, and there usually are, they come forward once the charges come out.
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