I took a look at the bag with the TI. The decomposing body radiated its heat through the bag, and it had the clear shape of a four-legged animal. This lowered our concern about how to treat the scene. We opened the bag and found a paw, confirming that it was an animal, not a human.
Tracking down small pieces of evidence, especially in poor lighting, can be a great challenge. Similarly, finding tossed evidence after a foot pursuit can be nearly impossible. However, if the items have any retained heat, a thermal imager can help locate the items quickly and easily.