South of the border, drug traffickers use every trick in the book to push mass amounts of marijuana into the United States.

As Memorial Day weekend approaches in Chicago, cops strive to get weapons off the street while drug dealers prepare for an influx of buyers.

Camera crews examine fentanyl's impact on addicts and how overwhelmed customs agents are striving to stop the flow. Also, a Boston dealer talks money.

Addicts, dealers and law enforcement officials speak about Baltimore's transformation into "the heroin capital of America."

A large shipment of cocaine is transported from rural Colombia to bustling Madrid. Smugglers beware: Police may be waiting to pounce.

As violent street gangs attempt to squeeze out the old guard in Atlanta, a bounty hunter prowls for gang-connected dealers.

On the rough streets of Oakland, law enforcement searches for a mysterious RB rumored to be driven by a high-profile drug distributor.

In the port city of Rotterdam in the Netherlands, cocaine kingpins employ fearsome hitmen to intimidate and silence suspected informers.