An entry control apparatus includes a pair of spaced barriers forming a pathway therebetween. The barriers are positioned adjacent a doorway to control ingress into and egress from a building or the like. An arm is pivotally mounted and extends across the pathway and permits free movement of people in one direction and selectively restricts movement in the other direction. A motion sensor is provided and a motion control system is associated with the sensor. The sensor and motion control system cooperate to selectively allow the arm to move to a normally open position for normal traffic in an approved direction. In the event a person approaches the apparatus, as if to exit, or move in the wrong direction through the pathway, the sensor detects the movement and effects operation of the motion control system that locks the arm against movement to prevent movement through the passageway. An alarm system can be provided to alert personnel that an unauthorized movement through the pathway may be underway.