a security cover for display cases includes cooperating generally l - shaped rigid frangible - resistant panels . a hook - shaped lower edge of each panel is coupled to an anchor rail fixedly mounted to the base of the display case . each panel is then pivoted upwardly to cover a portion of the display case . the panels include flanges along an upper terminal edge thereof . the flanges are mated together in a u - shaped lock bar and a lock to securely couple the panels together and enclose the glass faces of the display case in a frangible - resistant protective cover to inhibit breakage of the glass faces and theft of the contents of the display case .