This new law enforcement device can be mounted on police cruisers, then driven near a crowd to scan for guns, knives, and possibly plastic explosives hidden under clothing. The new technology works by bathing a subject with millimeter waves, then detecting the radiation reflected from it using a bolometer, a device capable of detecting and measuring small amounts of radiation. This makes it a significantly more powerful detection tool than conventional passive imaging systems. It can detect all metallic objects, not just magnetic ones. It can locate weapons by shape and location, and with enough sensitivity, it can image nonmetallic objects. It also has the potential to operate at a distance. Present metal weapon detectors are considered inadequate because of their limited range. Unlike conventional metal detectors, this system doesn’t require a cooperative subject. A prototype holographic camera that uses millimeter-wave technology has been produced by government high-technology laboratories. This could be used to conveniently and quickly obtain accurate and complete body scans. It is designed as a stationary scanner for airport use, not mobile police work. The system may someday be fully automated so that it would detect and identify a concealed object and then alert security guards to the threat. However, at this time it requires human operators to interpret the image. The focus is currently on reducing the time it takes for the system to scan a person and process the data in order to avoid bottlenecks at security checkpoints. The system also has the potential to protect against theft by identifying concealed items that people may attempt to steal from a museum, store, or nuclear facility. These new surveillance technologies add new fuel to the debate over the constitutionality of high-tech policing practices. The use of this device is covert and there is no warning of its use. The lab is aware of these concerns and is working to mitigate or eliminate them.