TV Guide Investigation Discovery Monday

After a single mother fails to show up for work, police find her brutally stabbed and her daughter missing from their home in an affluent gated community.

After the shooting deaths of a family in their suburban Baltimore home, investigators realize it's not a robbery gone wrong, but rather an execution.

An apartment fire reveals dead bodies and detectives find a psychopath who appears polite and gentle, then later as a pawn of imagined demons.

A crash on a North Dakota highway leaves one passenger dead, but the van's driver unscathed, and investigators see the passenger has deep stab wounds.

An elderly couple disappears one day and their bodies are found at the bottom of a well on their property, and the suspect is the couple's middle-aged son.

A mother's love is the most powerful in the world, for one Ohio woman, it will even overpower her fear of death; incapable of throwing out her dangerous son.

When single mother, 45-year-old Rainey Morin from Montana, begins a relationship with 46-year-old Robert Kowalski, she is unaware of his dark past.

Three men die over a span of a dozen years and no files are charged, but a new investigation begins, and all suspicion points toward just one person.

When Michael and Valerie Miller are found shot to death in 2009 in Webster Plantation, Maine, detectives discover that the shooter was seeking money.

When the bodies of Brittney Cosby and Crystal Jackson are found near a dumpster in Texas, detectives study the evidence and reveal the identity of their killer.

When 19-year-old Kathy Chou vanished from her hometown of Renton, Wash., her friends search for her, while detectives delve into her own family history.

A Virginia Beach massage therapist disappears before work, sparking a search, then weeks later, a cyclist discovers trash bags in a swamp.

After 24-year-old grocery store worker, Caroline Nosal, befriends her coworker 26-year-old Christopher O'Kroley, their relationship soon begins to sour.

When Kerri Harris discovers a hidden camera in the ladies' restroom at the food processing plant where she worked, she is later stabbed to death by a coworker.

Mystery shrouds a San Diego wildlife park when one of its valued employees goes missing, and investigators fear the most dangerous predator is not an animal.

When 28-year-old Melinda Schaefer is discovered dead in her office by a custodian, the police interview several witnesses and follow leads to find her murderer.

When an overly flirtatious neighbor relentlessly pursues a woman after her husband suddenly dies, her brother decides to move in to protect her from any harm.

The relationship between two neighbors sours when one accuses the other of stealing from him; tensions rise after accusations and backstabbing.

When a rash of break-ins shatters the peace in a close-knit community, the residents take sides along the fault lines and good friends turn into deadly enemies.

What starts as an idyllic relationship between neighboring best friends and business partners takes a wrong turn and ends up in a triple homicide.

The noise from a new neighbor's puppies turns a man into a vengeful menace who goes to war with the entire community, none of whom may survive.

After years of a married couple ruling their street, a new neighbor moves in, and after years of tension between the two parties, one is pushed over the edge.

When Yei and John Daniels come home on Christmas 2009 and find their house ransacked, but a few days later, a knock at the door changes their lives forever.

After being found guilty of murdering two young women and sexually assaulting seven others, even more survivors of the murderer have shared their stories.

In Arizona, a police officer and firefighter respond to a serious vehicle collision; in Florida, police pursue a suspect who chooses an unexpected escape route.

Colorado police search for answers as to who killed 27-year-old Andrew Jenicek in a strip mall parking lot as he was picking up dinner at a local BBQ place.

After being found guilty of murdering two young women and sexually assaulting seven others, even more survivors of the murderer have shared their stories.

In Arizona, a police officer and firefighter respond to a serious vehicle collision; in Florida, police pursue a suspect who chooses an unexpected escape route.

Colorado police search for answers as to who killed 27-year-old Andrew Jenicek in a strip mall parking lot as he was picking up dinner at a local BBQ place.

When Yei and John Daniels come home on Christmas 2009 and find their house ransacked, but a few days later, a knock at the door changes their lives forever.

After 25-year-old Brandon Horst is found dead with a bullet in his head at his home in St. Paul, Minn., the police investigate and reveal it to be a homicide.

When 35-year-old Sara Raras is found murdered on November 14, 1998, in her home in Maryland, the investigation quickly focuses on her estranged husband.