Which episode...

I am wracking my brain trying to remember which episode has a man cruising in a panel truck, looking for a gay guy to pick up. There are plenty to choose from but the one he stops for is suspicious and changes his mind about getting into the van. Within minutes, two cops stop the van and when they slide open the side panel doors, they see a dead naked body of a man on the floor.

Next, the driver is in the interrogation room, denying any involvement in a crime.

The more I think about this, the more I draw a blank. What happened after that? How did the dead man end up in the van. I know the driver was creepy but what did he have to do with the crime that was the central theme of the episode?

I know it's not that important - eventually, I'll come across the episode again. But if anyone knows the story, please clue me in. Thanks!