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.

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 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.

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 man finds his family slaughtered in their West Virginia home. The oldest son, 16-year-old Gavin Smith, is missing, he turns up hiding at his girlfriend's.

A 19-year-old woman vanishes, and the suspect is a former high school classmate with whom she had been communicating days earlier. The family is weary, for the suspect has a notorious past filled with sexual deviancy and homicidal urges toward women.

An unapologetic 14-year-old boy confesses to the murder of his best friend. Twelve years later, he's back in court with chance at a reduced sentence. Has this 26-year-old really changed? Or is he the same meticulous, cold-blooded killer he always was?

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.

After his wife vanishes from Jackson, Missouri., a psychopath plays cat and mouse with detectives.

Police respond to a 911 call to find a father of two dead in his home with more than 15 gunshot wounds. Police question the family, but one person is missing, his mother-in-law. Now detectives must determine if this grandma could be a deadly psychopath.

In rural Missouri, police receive a chilling call from a 50-year-old man who claims to have shot three individuals inside his home. Detectives discover that this impulsive massacre had a purpose, and that the culprit is a psychopath obsessed with control.

When a graduate student suddenly goes missing, the family he's staying with immediately contacts police. Then, just days later, a horrific discovery forces investigators to face a rare kind of monster.

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.

While being questioned in the abduction of an Anchorage barista, a young local businessman starts negotiating with investigators to reveal details of a depraved secret life as one of America's most meticulous and psychopathic serial killers.

A failed actor take out his rage on the weakest members of society; after killing four people, a chance encounter with police leads to his downfall; the interrogation room becomes the stage for this killer's final performance.

A concerned mother reports her 24-year-old son missing. He has fallen under the spell of a 47-year-old widowed woman. Detectives soon realize she's a sexual psychopath who has claimed the lives of more than one admirer.

The "Tourniquet Killer" terrorizes young girls across Houston, Texas. When advances in DNA finally lead to his arrest, this psychopath eagerly confesses to multiple murders.

Hikers in Portland discover the badly decomposed body of a raped and strangled young girl. A month later, another woman turns up brutally murdered in same fashion. The prime suspect is a homeless drifter harboring dark sexual fantasies.

A mother awakes to find her two sons with their throats cut. Their aunt's boyfriend confesses to his mother, and she wears a wire to capture her son. As he admits his guilt, it's clear how a psychopathic rage led to horrific violence and innocent victims.

A psychopathic son wanting control murders his middle-aged parents.

Traits of psychopath lurk in us all, but for whom does it lead to murder?

A 50-year-old woman is found dead in her home. All that's left behind is a note that reads, "Chase me." But when detectives uncover the killer, they quickly discover they have come face to face with a remorseless psychopath.

Weeks after an 18-year-old man's friend reports him missing, his clothing turns up burned in a trash can behind a suburban home. When witnesses lead investigators to a young man with a history of violence, they soon learn he had not worked alone.

A road rage incident turns deadly as an elderly man is beaten to death by a teenager who claims he was acting in self-defense. Detectives not only find holes in his story but uncover that he is a remorseless and utterly manipulative psychopath.

After coming home to find her parents on the floor bleeding, a woman's younger brother claims their father shot their mother before turning the gun on himself.

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 explore the anatomy of the key manipulative tactics of psychopaths.

After his conviction for the brutal slaying of his wife, a Florida inmate lays claim to another unsolved murder 17 years prior, revealing that he's a manipulative psychopath with a history of violence and an unquenchable thirst for revenge.

A home invasion leads to the revelation of a shocking double life.

Death row inmate John Hummel agrees to a final interview weeks before his execution.

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

An impulsive psychopath randomly kills a successful female executive.

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.

A mother who calls 911 to report her 32-year-old son is threatening her turns up dead in her home; he becomes the only suspect, and when he turns himself in, his pragmatic retelling of the slaying isn't just cold hearted, it's psychopathic.

A gunman shoots a man dead as he runs along a country road. First responders find a witness standing next to the body with a strange story to tell, and detectives will unravel the lies of a callous psychopath who takes out his frustrations in bloodshed.

A woman finds her elderly brother dead in his bedroom with his throat slashed. Uncovering the truth poses a challenge for detectives, as the individual responsible for killing him is a manipulative psychopath who craftily deflects blame.

A racially motivated serial killer on death row, who targeted civil rights leader Vernon Jordan and pornography publisher Larry Flynt, confesses to additional unsolved murders with the help of a shrewd female prosecutor.

A killer shoots a young woman dead in her boyfriend's Orlando apartment. Hours later, he turns up in a hospital bed 500 miles away with a gunshot wound and a bizarre story that unravels to reveal he's a lying, callous psychopath.

A man calls 911 with his dying breath, and first responders arrive to find him brutally murdered, stabbed 59 times. When detectives question his best friend, they uncover a tangled, sick story of deception and jealousy that explodes in psychopathic rage.

« Previous Ep. Next Ep. » Investigators search a farm for a missing man and find human leg bone on the property. The owner, Susan Monica, admits that her pigs ate her tenant alive, and he's not the only victim. A ruthless psychopath, Monica despises humans but loves her pigs.

Terror rocks an Ohio town when a mother, her two kids, and a close friend vanish. Fearing foul play, investigators track down the prime suspect and uncover a house of horrors. Detectives find themselves dealing with a psychopath with a bizarre obsession.

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.

A vindictive psychopathic wife murders her husband.

A man finds his girlfriend and her mother murdered in their beds at night; he calls 911 for help, but police discover his urge to seek revenge.

Eleven operators receive a terrifying call from a youngster who claims he stabbed his parents to death. Unsure if the call is a Halloween joke, police rush to the area, only to learn that it is not a fake and that the caller is a budding psychopath.

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

A crash on a North Dakota highway leaves one passenger dead but the driver unscathed; when investigators see that the victim has stab wounds, they know there was foul play; detectives interrogate the driver.

A young girl disappears, and detectives find a psychopath who duped her.

A 33-year-old oil rig worker calls 911 to report his girlfriend missing. He seems to be helping in the time-critical hunt to find her. A failed polygraph test leads detectives to suspect this seemingly caring boyfriend is a psychopath.

Burlington Police get a call that a man killed his girlfriend. At the scene they find the man calm while his girlfriend's body lies nearby. He explains that he has other victims, revealing a history of psychopathic sexual deviancy.

Every parent's worst nightmare is the possibility that their child has the same evil traits as the most heinous murderers.

A man confesses to accidentally killing his best friend while cleaning his gun; during his interrogation, he stuns police by revealing that he’s behind a long trail of bloodshed and is a serial killer who seems to consider himself an angel of mercy.

Searchers for a missing woman find her brutally beaten body in a dilapidated house near her home. The case goes cold until a local teen steps forward to reveal that he's not only the killer but also a manipulative psychopath with a thirst for violence.

Police find a 17-year-old female's dead body in a ditch with two gunshot wounds. The investigation centers on two friends of the victim claiming her death was an accident, but detectives uncover it was a thrill kill carried out by evil psychopaths.

A New Hampshire village is in shock after four adolescents were arrested for robbing and murdering a 42-year-old mother and maiming her 11-year-old daughter. Detectives discover two individuals who are vicious psychopaths rather than ordinary criminals.

A man crashes into the back of a woman's vehicle early one morning. Officers respond to the scene only to find her car abandoned. Witnesses point to the other driver, and detectives are horrified to discover a sadistic psychopath who admits to murder.

When a 64-year-old grandmother does not return home from her morning walk, local police uncover that the man responsible for her disappearance is not only a pathological liar but a sexually deviant psychopath carrying out a twisted fantasy.

After a house fire in Texas, suspicion lands on John Hummel when his family's brutally murdered bodies are discovered in the ashes, and he doesn't blink an eye. Now an inmate on death row, he grants a final interview weeks before his execution.