Vengeance: Killer Neighbors

A mother who is also a recovering addict is stabbed while standing up to the neighborhood bully, and grainy video and unreliable witnesses may stand in the way of investigators determining who was holding the knife that killed her.

A front yard brawl between two Euclid, Ohio, families leaves one person dead and investigators wondering how teenage heartbreak started it all.

When a gay rights activist is stabbed to death in his own apartment, police are tasked with tracking down his killer -- and in the process, they uncover a dark world of paranoia and delusions lurking in the heart of London.

When a man is gunned down in front of his Denver home, investigators discover evidence of a neighbor's deadly plotting, but it takes six years to track the killer down.

When a wealthy neighbor begins buying up Montana land and restricting access to the public mountain trails, one man cuts the locks and ends up dead.

When police arrive on the scene of a barbeque-turned-bloodbath, they begin to unravel a neighborhood feud that pushed one man to the point of no return.

When the sounds of gunfire erupt in a usually quiet, Minnesota suburb, the police begin receiving frantic 911 calls. One such call is from the shooter himself, a man who police soon learn became unhinged over the sight of too many deer.

A giant barricade is erected between property lines in an attempt to resolve bad blood between neighbors, but it doesn't stop their animosity from escalating out of control and resulting in a brutal murder.

When tensions boil over between neighbors in a Florida small town, a local waitress and her family fall victim to a poisoning. Investigators must track down the mastermind behind one of the most cunning murder plots they've ever seen.

When a Tennessee man is shot down in front of his own home, police use home video to unravel the history of a vicious feud between rural neighbors -- and determine whether the shooting was self-defense or cold-blooded murder.