Very few criminals decide against felonies like murder or armed robbery for fear of a misdemeanor fine for illegal concealed carry. So, the issue is about citizens who would not consider carrying a weapon to commit crime. These people will be trained and registered with the state under the law. Police will have to treat every traffic stop as if the subject was armed. In the 31 states that have this law, no concealed weapon licensee has ever been charged with shooting an officer.
Criminals are very unlikely to apply for a picture I.D. to commit crimes with firearms.
People are more likely to be killed with their own gun than to kill an attacker. Guns are used up to 2.5 million times per year for protection.