Under what conditions should a RADAR unit be removed from service?

A RADAR unit is a critical tool for law enforcement officers, and maintaining its functional integrity is essential for accurate enforcement. Each option listed addresses important aspects of the RADAR unit's operation. If any lights on the display are malfunctioning, it could prevent the officer from receiving important visual feedback about the unit's status or warnings that are necessary for safe and effective use.

Audible alerts are equally vital, as they provide immediate notice of operational issues or alerts that require the officer's attention, particularly in fast-paced environments. If these alerts fail, it could lead to undetected malfunctions or misinterpretation of the data being presented.

A tune test is a procedure that ensures the RADAR unit is functioning properly and accurately reading speeds. If this test fails, it indicates a critical issue with the unit's calibration or functionality.

Since all these components are essential for the proper operation of the RADAR unit, removal from service is warranted when any of these malfunctions occur. This approach ensures that only fully operational equipment is used, maintaining the integrity of the enforcement process and helping to uphold lawful practices in traffic regulation.