I think that the Crown attorneys already have the right to decide what types of charges are going to be laid. In my experience in Manitoba, when a person is arrested for a crime, the police department brings the evidence to the Crown attorney, and the Crown attorney examines the evidence. My assumption, maybe incorrectly, is that the Crown attorney looks at what offences have contravened what laws we have. That's what they base their decision on what charges are to be laid. That has been my experience.
Maybe I'm not the best person to speak to this in terms of what you're asking, because my understanding is that they lay the charges according to the laws that have been broken.