In Commonwealth v. Jovani A. Garcia, the defendant was charged with possession with intent to distribute crack cocaine. Two detectives were doing undercover surveillance in a "high crime area" at the prompting of neighbor complaints. One detective was in an unmarked vehicle, while another was near a residential building.
A detective saw a car turn right on the street, stayed still, drove north, and then made a U-turn to drive south again. Around the same time, a man came out of the building. The detectives were familiar with him. They described him as "light-skinned" and "Spanish." The man got into the car's back seat. The car traveled a short distance and stopped, whereupon the man got out and went back inside the building and the car drove off.
The police believed they'd just witnessed a drug transaction. They radioed takedown detectives to stop the car. At the stop, the takedown officers discovered 3-4 bags of crack cocaine on the front seat.