Michigan's concealed carry law went into effect roughly ten years ago. The Free Press has an article that admits that the fears of the opponents of the law were nonsense. Several opponents who were interviewed, including various prosecutors and police, admit obliquely that what they said would happen didn't.
10 years after concealed weapons law, unclear why many in state were gun-shy
Of course, it didn't take a genius to see that they were wrong. You only needed to look at every other state that has a concealed carry law.