Am sure your community has some sort of "Snitch Hot Line" just call it and explain he's been taking naked pictures and smoking marijuana with your 14 yrs old sister, your scared of him he's a very dangerous drug using criminal and fear for your safety. Just call from a pay phone and explain your worried about him finding out, you'll be in serious danger, ask for the persons name you talk too, makes it sound much more legit... Rehearse before you call, this'll atleast require a detective to make an apperance..