I'm thinking about turning in a drug dealer........?

I have vast knowledge of an individual who sells heroin in our metro area of 400,000+ people. He will sell to anyone. I want this individual OFF THE STREETS OF THE TOWN I GREW up in, but this town has a high rate of retribution, and I don't want to die for it, but I suppose it would be a noble cause, to die almost as a martyr.... I understand the function that drug dealers serve. The have a job just like anyone else, but this one killed a friend of mine. He's willing to sell to me. Do I set up controlled buys with the police? Do I risk my life? Or do I stay silent and clench my teeth? I could always shoot him, but I don't want to go that way. That's the way so many people of this town have gone before and they've all ended up in prison. I won't do it. I just want to know how to solve this problem... It haunts me every day and I can't bring myself to do anything. I just need advice. The police in the town (all the cities are contiguous) are OK. I wouldn't call them trust-worthy, but I'd call them half-way honest. The thing is: if I go ahead with this, I want to be able to explain the situation to an EXPERIENCED Narcotics investigator, get his advice (with my lawyer present of course, and NOT in the police department. I'm talking like OVER LUNCH or something). I know he/she'll be recording the whole thing, so I have to watch what I say, but what this dealer has been doing HAS to come to an end in our city (it's actually the city my parents live in. I live a ways down the road). Obviously there are many, MANY more details, but they won't be divulged here. Any answers from the public, and especially law enforcement would be helpful... I know that my info is easily accessed, and thus, I am easily accessed. Fortunately I have dual citezenship, and it's not to Canada or Mexico. So, should things turn ugly, I can always flee the US. I don't want it to come to that. I just want this guy OFF the streets of the town that I "live" in. Please help.