Chicago Tribune - an interesting article about concealed carry guys acting properly - then there's this:
Later that month, a man attempted to help police foil an armed robbery at a south suburban Crestwood phone store by firing at the fleeing suspect. A police officer had to duck for cover when the unidentified license holder fired at the suspect.
None of those shooters was charged. Illinois law says firearms can be used in cases of imminent danger and in defense of self and others.