Again, your average criminal understands how to hide from headlights, street lights and your flashlight. He does not understand, or even contemplate, trying to hide his body heat from a thermal imager. By scanning a high crime area, you may see hookers and johns duck into the shadows of an alley, or watch a hand-to-hand drug deal in the corner of a park. You could even watch the LFA thug get ready to smash another car window to grab a stereo.
Depending on the quality of your TI, the ambient temperatures and your comfort with the device, you may or may not be able to identify key features of a suspect. Eyeglasses, beards, heavy coats and hooded sweatshirts may be discernible on a TI display. However, you and your partner will probably have to plan an approach to get up on the suspects and actually put "hands on." If your manpower and call volume allow, you could even set up an observation team and a contact team.
When the suspects profess their innocence and claim that they didn't do anything wrong, you can confidently inform them, "I saw you do it."
Night time is always a challenge for patrol officers. Poor lighting and higher criminal activity normally means we have to rely on bright lights to catch bad guys who know where we are and where we can see. By creatively deploying thermal imagers on the streets, officers can not only secure perimeters, they can also watch high-crime areas covertly. The ability to be covert with a TI gives us as officers a huge advantage, because we all know, when people think the police aren't around, they act like their natural selves. And sometimes, that's exactly what we want.