Most of the crime and killings happen not because of intoxication but because the trade must be clandestine.
B.S. drug addicts can't afford the habit because they are too burned out to work. They'd still be robbing, breaking into houses and killing to get the money for their fix even if it were "legal". They'd still be sharing needles and the aids, hepatitis, etc. that goes along with it.
They'd still overdose, wind up in hospitals under taxpayers dime getting cleaned up. They'd still be patronizing methadone clinics, they'd still wind up in prison or mental institutions, all of which is a burden to taxpayers.
If it were 'legal' the government stuff would still be crap, and better, tax free "street drugs" would still be sold underground. The whole idea that "legalized drugs" would solve any problems is laughable. Those that propose it obviously haven't thought out that argument very well, probably because they are too stoned to think.
Legalized would only mean government controlled, like tobacco and alcohol. It is still illegal to smuggle tobacco and alcohol. There are still laws governing possession amounts. That's why there are still tobacco and booze smugglers.
And if the use of cocaine was legalized, presumably more people would use it, more people would abuse it, and more lives and families would be ruined.
There's no panacea for fighting the war on drugs, just like there is no panacea for fighting the war on first degree murder.