Expanding on an point by grimtrigger, is this related to damage per user, or overall damage? If governments no longer controlled heroin, and the number of users spiked to be the same as the number of users of alcohol would the graphs change.
I suspect that because of dependency, strong drugs would still lead to increases in crime, since they would still cost something, and their users would still not be in a position to productively earn to feed their habit especially as they got deeper into the addiction.
You suspect wrong on both accounts. Many governments have legalized Heroine. Doing so has always lead to marked decreases in use. Lower use means lower demand means less drug related crime.
Additionally, when money saved on drug enforcement is appropriated for needle exchanges and rehab centers, the price of a days worth of heroin drops to 0 for the user. Areas with decriminalized heroin and needle exchanges see the greatest reduction in use and drug related crime.
I suspect that because of dependency, strong drugs would still lead to increases in crime, since they would still cost something, and their users would still not be in a position to productively earn to feed their habit especially as they got deeper into the addiction.