Described herein is a locking device and method which integrates mechanical components in a hollow metal door frame with electronic access components. The electronic components override the original mechanical components of the lock to create a fail-safe situation in which the original mechanical lock may be disabled. In the preferred embodiment, my upgraded locking device can be re-installed within a hollow door frame, thereby minimizing service costs and doorframe modification costs. The electronically controlled component can be a cam retaining locking bar which contains a roll pin and an open area bordered by two cut sides. The open space eases lock installation with a door by avoiding protruding door structures such as metal tabs.