A device determines drug/alcohol content level in the breath of a person (1) with a stationary monitoring device (2), a communication unit (5) for data transmission to a central computer unit (4) and a hand-held device (3), connected via a data interface (6). The hand-held device has a mouthpiece (7) to receive a breath sample in a sample-receiving unit (18). An analysis unit (8) determines and transmits a drug/alcohol level via the data interface (6) to the monitoring device (2). A camera unit (16) records a skin area (13) of the person (1). An identification unit (9) makes a comparison of a recognized pattern on the skin with a pattern stored in a memory and a control signal is generated in case a pattern deviation. A control (10) is configured to transmit image data and/or a violation of the rules for performing the test if a limit value is exceeded.
