Killer Motive

A toxic relationship between her son and his on-off-girlfriend led to the fatal poisoning of chiropractor Mary Yoder.

Nearly four years after vanishing without a trace, the remains of the McStay family were found in the Mojave Desert.

A young mom was gunned down as witnesses — and her 18-month-old son — looked on. Who could do that? The answer was found close to home. 

After finding Martre Coles' body disposed of "like trash," officials made the difficult decision not to inform his family and instead put them under surveillance. 

When the beloved “first lady” of a church was strangled to death, investigators turned up infidelities, a secret cell phone, and a wall of silence from her congregation.

A shaky alibi and a $400,000 insurance policy made Melissa Oxley a prime suspect in her husband’s brutal shotgun murder.

When a respected Navy officer is strangled in a Florida motel, investigators search for a motive tied to his military past and current marriage.

Brian Davis was shot dead along a Louisiana dirt road. Was it because of his philandering? Or finances?

Jim Kauffman was accused of operating an illegal drug ring with a motorcycle gang as well as having his wife killed to avoid exposure.

This Valentine's Day weekend, Oxygen has programming all about the dark side of love, including a two-night special event, "Lover's Lane Murders."