An infrared camera is an ideal tool for law enforcement agencies to
detect the thermal signature of a criminal suspect in the darkness of
night. The pursuit of suspects in moving vehicles at night is
considerably aided by infrared technology. The vehicle's engine and its
tires (because of friction with the pavement) both become hot, producing
an infrared glow that is easily detected and monitored. These thermal
characteristics make infrared cameras particularly useful in traffic
surveillance, especially in dark or foggy conditions.
The use of IR sensors is also widespread in perimeter surveillance, in
monitoring the US border for illegal immigration, the detection of
concealed weapons and other
hidden evidence, and for locating hidden graves.
Thermal infrared evidence has been used to obtain warrants and
to convict criminals and is even used by investigators to
reveal hidden text. Several
court precedents already exist for the use of evidence
obtainable with infrared technology.