In a newsroom, correspondents Sara Rogers and Michael Taylor select footage of shootings for a report about increasing criminal activity since John F. Kennedy’s assassination in 1963. The report airs on television as a large Italian family gathers for a going-away party in South Philadelphia, Pennsylvania. Later, John D’Angelo helps his relatives load a moving truck, and his pregnant wife Lisa asks if they can move to Colorado before their baby is born. While the couple drives through a run-down neighborhood, Lisa jumps out of the car to stop a pimp, Eldorado, from beating one of his prostitutes. Angered, the attacker speeds after the D’Angelos until John crashes into a house. John points a gun at Eldorado’s face, but Lisa falls to the ground with labor pains, and John takes her to the hospital, where the baby is declared dead. While working in his delicatessen one night, John insists his son, Danny, walk his grandmother, Vera D’Angelo, home. They enter a nearby pharmacy during a robbery, and one of the masked criminals steals Vera’s ring by cutting off her finger. After the criminals flee, John runs into the store and calls an ambulance. At the hospital, John yells at the police over their slow response time. Lisa visits her husband and insists that they move out of the city. At home, John looks at happy photographs from his childhood in the neighborhood, and Lisa threatens to leave him if he does not agree to relocate. That winter, John spots Eldorado’s car outside a bar. He goes in and attempts to shoot the pimp, but his police officer friend, Vince Morelli, drags him away. In his deli, John hosts a meeting of his friends and family to discuss making citizens’ arrests of local criminals, since the police are unable to keep the streets clean. At their new headquarters, named the “Peoples’ Neighborhood Patrol,” the men learn how to administer CPR and purchase patrol cars. Later, they walk through the bar wearing “PNP”-emblazoned vests and caps, and John starts a fight with the bartender, which escalates into a brawl among the patrons. The D’Angelo family visits John’s mother, but she refuses to see them. One night while driving the PNP car, John and Vince alert the police to a burning building, and beat up the two arsonists. When the officers arrive, the detective takes John and Vince to the station for questioning, but determines they have done nothing illegal. Upon returning home from the store with Danny, Lisa discovers that the house has been broken into and destroyed. Upstairs, Lisa finds their dog’s mutilated, bloody body hanging in the shower. In the newsroom, Sara Rogers and Michael Taylor review stories about various self-defense vigilante organizations, including a newspaper article on John’s patrol team. John meets with Ivanhoe Washington, the African American head of a community outreach group, hoping he can help find the robbers who hurt his mother. Washington, however, insists the issue of local crime is deeply rooted in race, and is offended by John’s willingness to criminalize black people in poor economic situations. Meanwhile, two PNP officers find Eldorado outside a strip club, where he shot a man. Distraught by the murder, a stripper tries to attack Eldorado, but he drives away. One morning, at the deli, a group of Italians arrive to thank John for his services and present him with a sash of red, white, and green. Among the admirers, Sara Rogers invites John to step outside for an interview for the Michael Taylor show. Later, the reporters watch the interview video, in which John explains his motivations as a parent, hoping to protect the street for his children. Meanwhile, Councilman Hal Brusco urges the police commissioner to put an end to the PNP. John then meets with the commissioner, who also criticizes him for his racial insensitivity, but John refuses to back down. One afternoon, he stops a mugger in the street, hanging him from a meat hook to set an example. After a politician proposes that John run for city council, Lisa is hesitant, because she believes her husband is neglecting his responsibilities at home. While eating dinner, John notices his son’s friend behaving strangely, and realizes the boy has injected heroin. Although Danny is not using drugs, he helps his father track down members of the drug ring, including an Italian restaurant owner claiming to be protected by the Mafia boss, Donato. John meets with Donato, who gives him an old, Italian coin that he says people will recognize as a symbol of respect. When John shows the coin to the restaurant owner, the two men fight until the kitchen is destroyed. That evening, Vince admits that his affiliation with John’s aggressive behavior could cost him his job. One day, Washington shows John two men, one white and one black, and claims that one of them is the robber who cut off Vera’s finger. John beats the black man, immediately assuming him to be guilty, but Washington reveals that it was the white man. One night, Eldorado reports an assault in the park and shoots the on-call PNP officer. When John arrives, he discovers that Vince was the victim. At the funeral procession, Vince’s wife and a number of police officers walk alongside John and the PNP to indicate their support, increasing John’s public profile. Determined to make good from Vince’s death, the PNP closes the park where their friend was murdered, beating the criminals who congregate there. When Eldorado drives his car through the crowd, John speeds after him and crashes into the vehicle, causing it to explode. The pimp runs away on foot, but John is tackled and handcuffed by police. The commissioner shows him a report containing profiles of the three men who shot Vince, which includes Eldorado, and promises to arrest them. The PNP establishes a library in Vince’s name and kick-starts John’s campaign for city council. John sneaks away from an election-night party and follows Eldorado to a strip club. He fills a balloon with water and attaches it to a grenade, which he drops into Eldorado’s car and watches it explode. John returns to the deli in time to hear a news report announcing his victory. That winter, children play in the snow-covered park, and Michael Taylor reports that the neighborhood crime rate continues to drop dramatically.