Motive to Murder

A Navy doctor is killed, his wife critically injured, exposing a web of secrets and betrayal.

In 2011, a gunman kills six and wounds 13, targeting Congresswoman Gabrielle Giffords in Arizona. Police arrest a disturbed 22-year-old with a history of alarming behavior.

A grandfather's disappearance in rural Utah leads to a multi-state search, uncovering a shocking murder by a father-son duo.

A teen's murder in Mansfield, Texas, reveals a chilling tale of obsession, revenge, and a love triangle.

In Houston, a brutal crime scene leads police to a petite woman who claims to find sexual satisfaction in killing.

Two robbers kill five employees at a Wendy's in Queens, New York, leaving two others for dead. A survivor's testimony unveils a story of revenge and betrayal.

A drug-fueled killing spree terrorizes a small California town, where police uncover two childhood friends who kill for thrills.

In an Australian town, bodies of women are found with strange marks, leading police to a 20-year-old man who claims to be following a "sign" to kill.

In 1986 LA, over 50 African-American women are found dead, dumped in the trash. The killer is caught when he is seen pushing his latest victim in a shopping cart through the streets.

A police reservist finds a mass grave near Johannesburg, linked to a child advocacy leader who targets women resembling a mystery woman from his past.

A homeless man finds body parts in a North London dumpster, leading police to a killer. The case breaks when a suspect's door reveals weapons and a dismembered victim.

Lizzi Marriott, 19, goes missing, and Kat McDonough admits she offered her to her abusive boyfriend, Seth Mazzaglia, who killed her.

A respected English doctor is suspected of killing elderly patients, and when a will is contested, the truth reveals him as Britain's most prolific killer.

In America's first mass shooting, a sniper opens fire from the University of Texas clock tower. As the body count rises, two cops and a civilian make a daring climb to stop him.

Young, female students have disappeared with alarming frequency from the college town of Santa Cruz, California. Mutilated body parts show up as a human jigsaw puzzle.

A man kills seven in a Honolulu office, and police find a disturbed suspect haunted by his mother's ghost and paranoid of his co-workers.

Patients in New Jersey and Pennsylvania die mysteriously, leading to a meek man seeking control over life and death.

A fisherman finds a woman's body in Missouri, leading police to Richard Davis, whose camcorder reveals footage of assaults and murders of missing women.

A man in a Santa suit kills at a Christmas party in Covina, California, then flees with cash and a plane ticket, revealing a shocking motive.