RAY: This Puzzler was submitted by Tim Pugh. A detective is on a stakeout, watching a warehouse where he knows a bunch of crooks meet. But he wants to catch the boss.

He's watching this warehouse at night from a second-floor window in a nearby building. Crooks come and go all night, but he waits until the boss shows up to move in. Thing is, he doesn't know what the boss looks like.

All he knows is that the boss always travels with two bodyguards and that he'll be in a white car. Eventually a white two-door coupe pulls up. There are only two men in the car, and they get out of the car and go into the building. The detective waits. While waiting, he nods off for a few minutes.

When he wakes up the coupe is gone. He watches another half-hour and falls asleep again. When he finally wakes up, the same white coupe is back.

Using his binoculars, he looks into the car. He sees that the car is empty, but he knows that the boss is inside. He calls his back up, and the joint is busted. They catch the big boss.

The question is: How did the detective know the boss was inside?