Drugstore Cowboy

Bob Hughes is the leader of a crew of drug addicts consisting of him, his wife, Dianne, his best friend, Rick, and Rick's girlfriend, a teenager named Nadine. Together, they travel across the U.S. Pacific Northwest in 1971, supporting their drug habits by robbing pharmacies and hospitals.

After successfully robbing a Portland, Oregon pharmacy, they go straight home to use the drugs they just stole. During the process of getting high, a local low-life named David visits the group in search of hard-to-find dilaudid. Bob lies and says they have none but offers to trade him morphine for speed instead. David initially declines, but Bob talks him into trading anyway. After David leaves, the police bust down the group's door and the lead detective, Gentry, correctly assumes they were the ones who robbed the pharmacy. The police wreck the apartment while searching for the drugs but are unable to find them because the group wisely buried them outside. Read more on Wikipedia.