[traditional1]

"Since only the rapist and the victim smoked at the scene, that's a pretty big clue."

That assumes no one else had previously smoked in the room, or afterward, before the evidence was even collected?

[MeanWestTexan]

Well, that's what the victim said.

I've read about this attack other places.

The rapist smoked cigs with the victim (an event that is stragely common).