Luis Frias makes John Walsh's most-wanted list after allegedly stabbing his common-law wife to death in front of their children; Callahan Walsh explores the case of Harold Butch Knight, who left a trail of clues after confessing to killing his wife.

John Walsh spotlights freshman Jihad Ramadan, who allegedly introduces a knife to a fistfight that claims a star college student's life. Later, Callahan Walsh looks for Thayne Smika, who, police believe, shoots his roommate in cold blood over back rent.

Raymond "R.J." McLeod seems like a knight in shining armor to one single mom, but as John Walsh reveals, she was far from safe. Callahan Walsh discovers how rapper Maurice Nesbitt's constant abuse of his girlfriend eventually turns deadly.

Salvador Vaca Garcia tearfully appears on local news when his girlfriend vanishes. John Walsh scrutinizes Garcia's story. Later, Callahan Walsh looks at Brian Keith Freeman who allegedly killed his fiancé when their engagement fell apart.

John Walsh investigates a whirlwind romance and the accusation that Lamont Stephenson strangled his fiancé and her dog. Callahan Walsh explores claims that Gloria Schulze is a freeloader drunk driver who repeatedly cheats the legal system.

John Walsh profiles Mike Bullinger's secret double life that police believe ended in a triple homicide. Callahan Walsh looks at the case of Tomas Magallon Gonzalez, who allegedly abused his stepdaughter for years before taking her life.

John Walsh profiles Juan Lazaro Abrego who is believed to have murdered his ex-girlfriend, a beloved teacher. Callahan Walsh investigates Derek Dean, a St. Louis man accused of shooting a pair of twins, killing one and wounding the other.

John Walsh follows the story of Glen Stark Chambers, who killed his girlfriend and then escaped prison (not once but twice); Callahan Walsh follows Jesus Salazar, a suspect of murder who eludes capture for decades.

John Walsh profiles John Blauvelt, a U.S. Army vet who is accused of waging a lethal war against his young wife. Callahan Walsh looks at Rudy Fernandez, whose teen romance with his high school sweetheart is believed to have turned deadly.

Alicia Osibin's neighbors trusted her, but John Walsh looks at whether she may be responsible for her own mother's murder. Callahan speaks with Andrea, alleged victim of Frederick McLean's abuse, who is still desperate for McLean's capture.

John Walsh investigates how Eric Jones, the son of a preacher, allegedly turned to murder. Later, Callahan Walsh tries to make sense of how a dispute over a dog could provoke Ricardo Villanueva Cordova to reportedly commit murder in broad daylight.

John Walsh explores the case of conman Edgardo Perez who allegedly preyed on older men until it turned deadly. Callahan Walsh heads to Boulder where teenage babysitter Chris Deininger confessed to abusing 29 kids in his care before fleeing.