Not directly, no, but most of the people that a violent drug dealer murders probably don't seek out said drug dealer of their own free will and pay for the bullets/knives/etc that end their lives. Addiction is difficult to overcome, but not impossible. Not to mention these people weren't always addicts. They dug their own graves when they tried the substance the first time. Removing a drug dealer from society won't save/improve anyone's life.
Edit- I'll exit this conversation simply because I type too slow.
Edit- I'll exit this conversation simply because I type too slow.
Kinda like McDonalds.