A gang is a group of people who share a common purpose; they could engage in criminal activity like drug dealing, graffiti, and violence; and often have a common name, symbol, or color.
Heroin is a drug that is synthesized from morphine, a naturally occurring substance extracted from the seed pod of the Asian opium poppy plant.
At the root of “con man” is “confidence man” — a person skilled at gaining trust and confidence, then using it against their victim, most often to steal money.