After a woman is stabbed to death outside her apartment building, and no witnesses are willing to speak to the police, Mannion moves in, hoping to gain the residents' trust. The housing project has been a dangerous place to live for a long time, and the residents are wary of the police, who never seem to be there when they need them. Now, Mannion must convince them that this is not a media stunt - he honestly wants to make their lives safer - and that they need to speak up before the killer strikes again.

When a 7-year-old boy shoots two children, Mannion makes it his mission to find exactly how the boy got his hands on a gun. When Mannion questions the 7-year-old, he learns the youngster took the weapon from his 15-year-old brother, who reveals he got the gun from a "guy on the street" near his school. With the help of Temple and Debreno, Mannion sets up a sting and discovers that the weapon was a gun that the police had confiscated in a "buy-back" program. With the Public Safety Commission breathing down Mannion's neck, he must track down the culprits before any more guns hit the street or children get hurt.