Many, many thanks for the input and advice. I did speak to the couselor (delays in getting the consent). Apparently he left treatment because they told him up front he'd likely need a year long program.
The recommendation was to press charges. I'm deeply worried, but now firmly believe its the right thing to do. I will pray that it happens quickly and makes a difference, but I do now realize I'm not responsible for the outcome.
It was very important for me to hear from people who've been there, on both sides of the fence.