Keypad locks are security devices used to electronically lock doors to keep unauthorized personnel from entering into an area. Typically, they cannot be bypassed unless the person using it inputs the correct code (which can range in digit spaces). The words "ACCESS GRANTED" or a flash of a green light on the keypad lock device will notify the user that the code they entered in was correct. Additionally, a denied access notification and red light will notify the user that the code entered in was incorrect. With thermal vision, it is possible to see the heat signature left on keypad locks after a person uses it.