I lived in that area for 18 years, before I moved away to college. I can tell you that 10 years ago, there were serious drug and gang related problems. It wasn't "just a little pot." It was a very scary place to grow up. I'm so glad to hear that someone who is in a position to do something is beginning to address the issue.
I have my own theories for why no one else seems to have identified the problem. VERY FEW of these drug addicts are going to tell a teacher or school counselor straight up that they are using these drugs. They aren't even going to hint at it. In fact, this student would avoid the school counselor at all costs for fear that they would get "caught." They hide it as much as they can. So the well-meaning cop posed as school counselor would never realize how bad the problem was.
The only way to get at an accurate figure is to talk to the students. When I went to Westwind, everyone knew who the gang-bangers were. Everyone. There was no question. But the teachers had absolutely no clue. The kid who punched the lunch lady? No, he was not in a gang. He was trying to gain acceptance by the gang, whose members are not nearly so stupid as to so openly declare themselves in such a manner.