A lot of times, when a dealer sells to a civilian, they don’t arrest the civilian. The civilian will leave the area, and that’s when law enforcement will arrest the dealer. But with the civilian not in the area, they lose the end of the sale, like the fact that they’d find the same color bag on him. When you can get a civilian and you match up that bag with the ten bags that are on the guy over here, you can make the inference that he’s sold to this individual. Similarly, if you see a hand-to-hand and then this guy has the same color of bag, boom, you got him.