US Patent 11749038 Facial recognition frictionless access control

An access control system can include a camera that detects an image regarding a subject, a database maintaining information, a facial recognizer that receives the image and identifies a facial feature of the subject based on the received image and the facial information maintained by the database, and a processor to alert security or another user when an authorized user accessing an area of a building is under duress, when an unauthorized user is accessing an area of a building by tailgating after an authorized user, when an authorized user has not provided two-factor authentication, or when an authorized user is in a particular area of the building.