System terminal integrated with biometric sensor, such as a fingerprint sensor. Transaction terminal such as a point of sale system, automated teller machine (ATM) or other system. The system may include a touch screen display. Also, logic to process sales transactions may be included. The transaction terminal may include a cash drawer. The system authenticates users based on data from the sensor, and can regulate access, for example to a cash drawer, based on the authentication. Also described is a sensor module, security system, and method of operating a transaction terminal.