Within the context of the OP and the title of the thread - Versed injection as a police weapon - I think there clearly are ethical issues inherent in such use.
This is not to say that there are not legitimate medical uses. Merely that the deployment of such drugs as a "weapon", and not in a situation in which the well being of the individual is the higher concern, that would seem to create a potentially unsolvable conflict in goals that should discourage its use in all public order enforcement situations.