Police engage in a massive manhunt to find a killer on a murder spree of revenge, taking the lives of his girlfriend, cousin, and a man he considers a father figure. Once captured, he proclaims that he simply wants to be "heard."

Authorities grow concerned when a 25-year-old woman reports her 50-year-old father and 6-year-old daughter missing. Police discover their dead bodies and uncover the shocking truth she is a psychotic killer.

For over three decades, Albuquerque police struggle to solve three violent cold cases. After years of searching, the cases break wide open when officers pick up a man on a probation violation. and he soon reveals himself to be a homicidal psychopath.

Pensacola Police are called to the Corner Store when a killer guns down a young man in a brazen public execution in the parking lot. Police track down their suspect and find a cold-blooded psychopath without remorse.

When a young mother goes missing, her husband joins the search while police discover her dismembered body in a stack of bins.

A vehicle plows down a 75-year-old military veteran on a country road in an apparent hit-and-run. When a young man confesses to the crime, detectives quickly learn they've encountered a psychopath with an intense desire to thrill kill.

Detectives reveal an unrepentant psychopath capable of executing the love of his life.

Investigators unveil the execution of a loving family, done by a callous psychopathic killer.

An early morning fire inside an apartment complex reveals the dead bodies of a young woman and an infant boy.

Police first arrest a man for discharging a firearm and soon discover dead bodies inside his apartment.

Psychopaths live among us. They can be friends, family members, coworkers, or even lovers. Trying as they may to impersonate normal humans, there are always signs that reveal their true nature: calculating, narcissistic -- and sometimes, murderous.

Experts look at a subset of psychopaths who are motivated by their heightened sexual urges and fantasies; this subset of offenders doesn't just enact physical violence but sexual violence toward their victims and is known as the sexual psychopath

A mother, her kids, and friends vanish in a bloody mystery., A slaughtered couple's son disappears. In both cases, young men toy with police, twisting facts and stalling for time. As lives hang in the balance, the truth hides behind lies.

Psychopaths live among us. They can be friends, family members, coworkers, or even lovers. Trying as they may to impersonate normal humans, there are always signs that reveal their true nature: calculating, narcissistic -- and sometimes, murderous.

A female executive's jog ends in murder. Also, DNA links a frail inmate to The Package Killer, a predator who hid women's bodies in alarming ways. As interrogations unfold, two seemingly ordinary men reveal decades of cold, predatory violence.