Things are not always as they appear.  One of these four individuals is not a harmless person sleeping in a car.  Can you tell the difference?

The Perpetrator is a lookout, keeping watch while their conspirators attempt to steal HVAC equipment off a nearby rooftop.  But the others are relatively harmless (if not entirely wholesome) individuals just pulling in to catch a few Zs or sleep one off.

Answer:

The Perpetrator in this case is to the top right.  How did we know something was wrong?  People who pull in to sleep or text aren’t several turns and twists deep in a parking lot, they don’t have pry tools in their truck, drug paraphernalia in the floorboards, and probably didn’t fall dead asleep this soundly when the text messages visible on the phone are actively still arriving as officer pulled in. 

When you know the property intimately you know where people end up pulling in, whether it’s to talk on the phone or sleep one off.  So when you see someone in an unusual spot it catches your attention right away, and from there everything else becomes possible.  But it’s the account awareness and familiarity that triggers everything.