TOMORROW ON ABC'S "20/20 SATURDAY"

In the first hour or tomorrow's two-hour "20/20 Saturday" on ABC, Amanda Knox sits down with Diane Sawyer for an exclusive interview (9:00-10:00 p.m., ET; OAD: 4/30/13).

In the second hour (10:00-11:00 p.m., ET), anchored by Barbara Walters, "20/20" pulls the blinds back on the nastiest neighbors around (OAD: 9/14/12). Reports include:

When Neighbors Strike Back: It seems everyone has a nasty neighbor story, but Kim and Greg Hoffman say theirs takes the cake, as their neighbor, Lori Christensen, a 49-year-old single mother and former Girl Scout leader, made it her mission to ruin the Hoffmans' lives. Her brand of terror was wide ranging - from verbal harassment, berating Kim in front of her children for being a recovering alcoholic, to incessant videotaping as the family comes and goes; from unwarranted calls to police and housing inspection authorities, to covering her garage door with bizarre and degrading signs - one that read:

"I Saw Mommy Kissing a Breathalyzer." But why?

Nasty Neighbors Story: A quiet, tree-lined road in Huffman, Texas, not far from Houston, is the scene of a neighborhood falling over the edge - one man's anger over a noisy karaoke birthday party explodes into mayhem and murder. When the gun smoke clears, Kelly Danaher, a young husband, father and teacher, lies dead in the road and his neighbor from two homes down, Raul Rodriguez, is charged with murder. But Rodriquez says he was justified under the Texas version of the Stand Your Ground law. During the trial, though, a picture emerges of a neighborhood simmering with deep and disturbing tensions, under siege for years, living in fear of one among them.

Celebrity Neighbor Feuds: What happens when the loud music is coming from your celebrity neighbor like Madonna's New York apartment or the LA pad of Justin Bieber? "20/20" takes a look at celebrities sparring with their neighbors.

David Sloan is senior executive producer of "20/20 Saturday."