BALTIMORE (WJZ)—Facing growing violence, federal agents and Baltimore City police together staged a huge undercover operation that leads to the arrest of dozens of people.

Investigator Mike Hellgren takes us inside the sting.

The ATF’s violent crime impact teams conduct raids in Baltimore’s crime hot spots.

Sky Eye Chopper 13 got rare video of one just a few months ago. They’re well planned, can be dangerous and provide extra muscle–done in partnership with city police.

Their latest operation was painstaking, starting in August in West Baltimore in the Franklin Square and Penrose neighborhoods, where violence had gotten out-of-control. Undercover agents came in to clean it up.

“Although these individuals haven’t been charged with that violence directly, they’re absolutely contributing to the violence in that neighborhood,” said Deputy Commissioner John Skinner, Baltimore Police Department.

Twenty-four people were arrested on drug charges. Police say they caught them in part by making covert drug buys.

“Individual criminals who impacted the city of Baltimore will not do that any further,” said Anthony W. Batts, Baltimore City police commissioner.

These ATF teams work with police in 31 cities across the country, including Baltimore.

WJZ went to the home of one woman who said her house was targeted in the raid. She said all the police allegations were lies involving her son, and then she started yelling uncontrollably.

“Wrong is wrong,” she screamed. “Take their side of the story, and I’ll meet them in court with it.”

Police say those arrested were not part of a single gang but were interconnected.

“Within that same geographic area you had a multitude of organizations selling their product, whether it was cocaine, crack cocaine, or marijuana,” said Major John Hess, Baltimore City police.

“This is what we can see in the results when you have that level of cooperation,” said Gregg l. Bernstein, state’s attorney, Baltimore City.

A risky, undercover sting–to make the streets safer.

The city state’s attorney says this is not over. More arrests are still taking place in West Baltimore.