What business is it of yours if your neighbor is doing heroin? We could get people off the streets if we gave them treatment. A drug addicts are sick; Locking them in jail shouldn’t be the answer
If junkies get their fix, it's literally the only thing they care about. It's them not being able to support their habit with a day job what makes them reckless and dangerous.
If junkies receive their fix from medical authorities, along with a treatment helping them to quit, they even have a hope to become in-addicted again.
Of course, arresting or maybe outright killing a junkie would instantly remove any threat to the neighbors. It just requires stopping to see the junkie as a human in need of help and start seeing the junkie as a violent criminal or even non-human. I wonder if such an approach is sort of dangerous for the society's mental health.