How we cite our quotes: (Chapter.Paragraph)
Quote #1
Speaking of savages, Bruce Cowell and his pack of jock-wannabes, who'd been kicked off every school team because of attitude problems and/or the use of illegal substances, were right on schedule for their weekly feats of dumbassery. (1.8)
When Deanna says "the use of illegal substances," she could be talking about pot, but in the context of athletics she probably means performance-enhancing drugs like steroids.
Quote #2
One of the things Darren and me have in common is that we both let Mom and Dad down. Him because of having a kid so young, not to mention getting busted for pot when he was sixteen and having to go through this whole court thing. (2.205)
Deanna doesn't mention Darren's arrest again, but since Tommy was his best friend, he definitely had access to pot. It's possible that Darren could even have sold pot to Tommy.
Quote #3
"Hang out after closing," he said, confident, like I wouldn't say no. "I've got some burnables." (4.2)
On the other hand, Tommy could have sold to Darren. If he did, he could have been indirectly responsible for keeping Darren trapped in Pacifica/his parents' house (even though, of course, Darren made his own choices).