A lockable keeper arm extends across an opening of a door strike housing. A pivotally mounted transmission lever releasably engages the keeper arm. A pivotally mounted release lever releasably engages the transmission lever. An actuator engages the release lever at a point between the release lever pivot and the transmission lever and drives the release lever between alternate positions in either fail-safe and fail-secure modes. The actuator engagement point may be closer to the release lever pivot point than the transmission lever engagement point. A stop limits travel of the release lever and may be positioned in alternate positions. In alternate positions, the primary lever unlocks the keeper arm when the actuator is either energized or de-energized, placing the strike in fail-safe or fail-secure modes. Magnets may be mounted inside the housing to attract metal particles. The actuator may be an electric solenoid or a motor.