As a person who tried "ALMOST" every drug at some point in his like, I NEVER understood injection. Our bodies come equipped with some incredible organs to keep out poisons and purging systems to keep us from accidentally killing ourselves. Inject drugs bypasses ALL of them...
It is a shortcut that just ain't worth it.....
But in this case, it sounds like this is a self-eliminating problem.
If heroin users are killing themselves off, I'd say that's more of a problem for the Sanitation Department, than the Police Department.