"The War in Chicago": A 48 Hours investigation

Tragic murders, senseless killings, pre-dawn police raids, parking lot busts of crooked cops, heroin addiction and a man risking his life to save his neighborhood from drug dealers. It sounds like something out of a movie. But the fact is each and every one of those scenes is part of the real-life drama we uncovered during our six-month 48 Hours special investigation, "The War in Chicago," airing Saturday night.

As correspondent Maureen Maher and I discovered, the war is a drug war played out on the streets of America's third largest city. It involves the Holy Trinity of Trouble -- guns, gangs and drugs -- tied to Mexico's ruthless Sinaloa cartel battling over Chicago's booming heroin trade. That is not an easy sentence to write. But it's all too true, according to a man who would know. That man is Jack Riley, a 29-year veteran of the Drug Enforcement Administration and head of the DEA's Chicago office and five surrounding states. He's a man devoted - obsessed - with taking back certain drug-riddled sections of his hometown.

Riley is straight out of central casting. A modern-day Elliott Ness, he fought a modern-day Al Capone in the form of Joaquin "Chapo" Guzman, the former head of the Sinaloa cartel.

In a major development, Guzman was arrested in Mexico in February 2014 and is awaiting trial there. But Riley's fight against the cartel's grip on the Chicago drug trade stretches on.

As part of our report, we shadowed Riley and his DEA-led "Strike Force" as they raided suspected heroin houses and took down crooked cops from a suburban police department. Riley is hardly the only real-life hero in our hour. Sadly, tragically, Anthony and Cleopatra Pendleton are as well. Somehow, in the wake of the senseless murder of their beautiful teenage daughter Hadiya - who came to symbolize the indiscriminate drug violence infecting the city - the Pendletons displayed unimaginable strength and grace in their interviews with Maher and the hours we spent with them behind the scenes.

David Muhammad is another hero. Instead of giving up when heroin dealers opened shop right outside his house, Muhammad fought back. Not with his fists...but rather a small digital camera. For months he videotaped the drug sales on the street outside his door - then posted them on YouTube at great threat to his life.

"David, I hate to be blunt about this," I told him at one point in our interview, "but one of these guys could just walk right up to you and say, 'You know what, it's over' and put a bullet in your head."

"If it's meant for me to leave here like that, I'll leave," said Muhammad.

Instead, he's still there. Still making a difference.

In the end, we hope the same can be said of "The War in Chicago."

The broadcast airs Saturday, June 28, at 9 p.m. ET/PT. Watch a sneak peek.

This story was contributed by CBS News Correspondent Armen Keteyian