From ABCNews.com:

The revisions expand the list of inspectors and enforcement officers who can legally possess and purchase the banned firearms to include sworn and certified officers at the department of motor vehicles, the chief state’s attorney office, the department of energy and environmental protection and some constables with police certification. It exempts such officers from the certificate requirement for long gun ownership, and allows them to maintain possession of assault weapons and large capacity magazines after their service ends by registering them.