SignalTrace technology links vehicle plates to personal electronic signals

A new surveillance technology called SignalTrace, developed by the company Leonardo, is capable of linking vehicle license plates to the electronic signals emitted by personal mobile devices. The system works by capturing public Wi-Fi and Bluetooth signals from devices inside a car—such as smartphones or headphones—to create what the company calls an “electronic fingerprint.” When combined with Automatic License Plate Recognition (ALPR) cameras, the system can associate these signals with a specific vehicle, time, and location.

While the technology is designed to assist in investigations by establishing patterns of movement and proximity, experts have raised privacy concerns. Nicole Bennett, a researcher at Indiana University, noted that even without direct identification, the ability to cross-reference data could connect vehicles to specific residences or workplaces.

Real-world installations of SignalTrace have been identified in Oxon Hill, Maryland, operated by the Prince George's County Police. Technical analysis suggests the system faces practical challenges, as electronic devices do not emit continuous signals, making it difficult for sensors to capture useful data at the exact necessary frequency and moment.