This is the shocking and gruesome mystery of John Wayne Gacy, a popular Chicago businessman and part-time clown who was leading a double life in the 1970s. By day he was a community leader and by night a predator of young men.

In Chicago, community leader and part-time clown John Wayne Gacy leads a double life, transforming into a monster who preys on male teenagers and becomes the most prolific serial killer of his day.

Charles Manson is a violent predator who has powers of persuasion that make it possible for him to convince his hippie followers to brutally murder innocent strangers

Charles Manson is a violent predator who has powers of persuasion that make it possible for him to convince his hippie followers to brutally murder innocent strangers

In Northern California, a masked predator meticulously plans his sexual assaults by studying the habits and routines of his female prey; after 27 years on the loose, police close in on the man they believe to be the NorCal Rapist.

In Northern California, a masked predator meticulously plans his sexual assaults by studying the habits and routines of his female prey; after 27 years on the loose, police close in on the man they believe to be the NorCal Rapist.

A look at the deal makers and hangers-on who attached themselves to Aileen Wuornos, who is known as America's first female serial killer.

A look at the deal makers and hangers-on who attached themselves to Aileen Wuornos, who is known as America's first female serial killer.

The Zodiac Killer terrorizes Northern California in the late 1960s; he taunts the public with cryptic clues, threats of violence and ciphers that are supposed to lead to his identity, but mostly go nowhere.

The Zodiac Killer terrorizes Northern California in the late 1960s; he taunts the public with cryptic clues, threats of violence and ciphers that are supposed to lead to his identity, but mostly go nowhere.

More than 900 Americans died in an isolated jungle in northern Guyana in November 1978; Jim Jones has gone down in history as a madman who drove his followers to suicide, but the truth is more complicated and tragic than that.

More than 900 Americans died in an isolated jungle in northern Guyana in November 1978; Jim Jones has gone down in history as a madman who drove his followers to suicide, but the truth is more complicated and tragic than that.

He is among the most infamous serial killers in American history. From 1976 to 1977, David Berkowitz terrorized New York City – under his creepy self-given moniker: the Son of Sam. Using a large caliber. 44 revolver, he unleashed eight horrific shootings across three different boroughs- wounding seven people and killing six. Despite an extraordinary investigation, and hundreds of NYPD officers working the case– Berkowitz’s crime spree lasted over a year. How did he get away with it? What clues did investigators miss? The detectives who worked the case tell the true tale of what it was like in New York City with a gun-toting murderer on the loose.

In 1977, the city of New York was being stalked by a seemingly faceless serial killer known as, “Son of Sam.” But after his final shooting took him to Brooklyn, a twist of fate and a little luck- led to his capture. The episode features interviews with detectives and psychologists about what he said after his arrest, why he did it… and how this quiet, soft spoken 24-year old post office employee from Yonkers turned in a serial killing monster.

In January 1974, four members of a family are brutally tortured and murdered in Wichita, Kansas. The murders shock the safe midwestern city, but little do they know, it is just the beginning. He calls himself “B.T.K.” which stands for Bind, Torture, Kill and for decades this bloodthirsty serial killer terrifies Wichita as he murders again and again and again. Wichita residents live in fear that they will be his next victim. Who is B.T.K. and will police capture this crazed killer before he strikes again?

B.T.K. stands for Bind, Torture, Kill., the name the serial killer gave himself. After terrorizing Wichita, Kansas with multiple killings from 1974-1991 he goes quiet. But he resurfaces in 2004 and residents of the midwestern city are once again petrified. For months he plays a cat and mouse game with law enforcement and the media taunting them as he seeks the attention he craves. But then… he makes a mistake. And when “BTK” is finally apprehended it is chilling to discover that he has been hiding in plain sight for years.

The summer of 1985 was one of the hottest Los Angeles had seen in a century. But terrified residents weren’t sleeping with the windows open, they weren’t sleeping at all. A killer was on the loose. And though the 1980s were considered the decade of the serial killer – one man stood out. He was the Night Stalker – his crimes were random, vicious and committed in the name of Satan. His victims ranged from toddlers to the elderly. And as the city was paralyzed with fear, he went unchecked while police struggled to stop him. Then the L.A.P.D. get a tip, a teenage boy spotted a suspicious car leaving a crime scene. Would it be enough to bring the Night Stalker to justice?

Through the record-breaking heat of the spring and summer of 1985 in California, a savage killer was on the loose. The Night Stalker had been linked to at least 15 murders from children to the elderly, male and female, wealthy and poor. Then police get a break – a tip from a teenage boy leads to the identity of the Night Stalker. Twenty-four hours later a mob of angry citizens track him down and capture him. But the man who terrified the nation for more than a year isn’t finished yet. His trial is a new, bizarre chapter that has some wondering if the Night Stalker will escape justice.

Santa Cruz, California was a mecca for the hippie generation in the early 1970’s, a beachside paradise where a university had recently opened. But this era of peace and love is shattered when female students began to go missing and their body parts start showing up around town. Police had no leads on who was committing these horrific crimes, but they soon realize that all the victims had something in common- they were last seen hitchhiking. A frantic public, desperate for answers, live in terror, waiting for the man they dubbed “The Coed Killer” to strike again. But no one could have expected that the person responsible, a local man, Edmund Kemper, was living among them, hiding in plain sight. He was a man with a dark history and a tortured childhood, a man who had killed years before and had now set his twisted sights on young women.

n April 1973, 24-year-old Edmund Kemper had murdered 6 coeds in and around the city of Santa Cruz, California, shaking the community to its core. But Kemper reached a breaking point, and what the public would soon learn, was almost impossible to believe. Told through interview footage with Kemper himself, as well as people who were there, this episode takes viewers inside the mind of a serial killer, from a childhood wrought with abuse through an early life of violence. Kemper outlines his motives for the killing spree and describes the terrifying methods he used to slaughter young women, operating right under everyone’s noses. As Kemper explains in great detail, he spared no one from his madness, not even his own flesh and blood. With his willingness to tell his story so openly, Kemper would go on, years later, to assist the FBI in profiling serial killers, offering insight into how, and why, killers like himself commit such horrific acts.

This is the unbelievable story of Robert Durst, the millionaire heir to a vast real estate fortune who has been linked to the deaths of his wife, his best friend, and his neighbor. For decades, Durst has been living under a cloud of suspicion. His first wife went missing in 1982, but the case went cold when there were no leads — and no body. Then, 18 years later, just as the investigation into her disappearance was re-opened, Durst’s best friend and confidante, Susan Berman, was shot dead inside her home. At the same time, Durst was hiding in Galveston, Texas disguised as a deaf mute woman. But when his neighbor’s dismembered body turns up in Galveston Bay, Durst’s story begins to unravel. He is quickly arrested, but he’s not in custody for long. After posting bail, he goes on the run. Where is Robert Durst?

Six weeks after jumping bail in Galveston, Texas, Robert Durst is caught on a store security camera in Pennsylvania shoplifting a sandwich and is quickly sent back to Galveston to stand trial for the murder of his neighbor, Morris Black. He would tell a jury he killed Black accidentally in self-defense, and he’d be acquitted of murder. But his story doesn’t end there. Durst decides to give a revealing look into his life in the six-part series “the Jinx” where in the final episode he is overheard in the bathroom muttering to himself, “killed them all, of course.” Before the episode airs, Durst is arrested for the murder of his best friend, Susan Berman. Now as he stands trial in Los Angeles, will his own words come back to haunt him?

Michael Swango – High school valedictorian; Distinguished Marine; Trusted Doctor… Serial Killer. For nearly two decades, this physician-turned-murderer left a trail of death and mayhem across two continents. Hear from the local and federal authorities who brought his reign of terror to an end, while facing down one of the most crafty and cunning medical serial killers in US history. Interviews include survivors from Michael Swango’s poisoning sprees, his former colleagues, families of his victims, federal and local investigators, and a Zimbabwe journalist who helped uncover a series of murders in a rural African hospital.

Dr. Michael Swango took an oath to “do no harm”… But he did just the opposite. Suspicious illnesses and deaths followed this once-trusted physician-turned-killer from hospital to hospital for nearly two decades and across two continents. His prey – unsuspecting coworkers and helpless patients. What would make a well-respected doctor become one of the most prolific serial killers in the U.S.? Interviews include survivors, Swango’s former colleagues, families of his victims, federal and local investigators, and a Zimbabwe journalist who helped uncover a series of murders in a rural African hospital.

The Golden State Killer invaded homes, tortured and terrorized families, committed fifty brutal rapes and thirteen vicious murders, and was on the loose for forty-four years. Cold case Investigators chased down thousands of leads without ever getting their man. But a new forensic tool breaks the case and exposes this remorseless predator – Joseph DeAngelo – his family, his background, and his life story; and finally, scores of victims get a measure of long-awaited justice.

he Golden State Killer invaded homes, tortured and terrorized families, committed fifty brutal rapes and thirteen vicious murders, and was on the loose for forty-four years. Cold case Investigators chased down thousands of leads without ever getting their man. But a new forensic tool breaks the case and exposes this remorseless predator – Joseph DeAngelo – his family, his background, and his life story; and finally, scores of victims get a measure of long-awaited justice.

The Butcher Baker was one of the most prolific serial killers in Alaska's history. For more than a decade, he kidnapped young women and brought them into the wilderness where he stalked them like prey. He got away with his crimes for years, living a double life as a soft-spoken baker and church-going family man by day, and prowling the streets and strip clubs at night, looking for more victims. But when one woman escaped and lived to tell her harrowing story, police made a shocking discovery inside Robert Hansen's home, which would expose the baker as the monster he truly was.

The Butcher Baker was one of the most prolific serial killers in Alaska's history. For more than a decade, he kidnapped young women and brought them into the wilderness where he stalked them like prey. He got away with his crimes for years, living a double life as a soft-spoken baker and church-going family man by day, and prowling the streets and strip clubs at night, looking for more victims. But when one woman escaped and lived to tell her harrowing story, police made a shocking discovery inside Robert Hansen's home, which would expose the baker as the monster he truly was.

In November 1974, six members of the DeFeo family were found murdered inside their beautiful seaside home. The mother, father, and four of their children were shot in the back as they lay sleeping in their beds. The bodies were discovered by the only family member left alive – the oldest son Butch DeFeo. What really happened that night in Amityville? Who murdered the DeFeo family and why? What caused the strange events in the house near the sea? Parapsychologists and psychics descend on the house to investigate claims of levitating objects and demonic possession in an attempt to explain why, 50 years later, this house is still a source of nightmares.

In November 1974, six members of the DeFeo family were found murdered inside their beautiful seaside home. The mother, father, and four of their children were shot in the back as they lay sleeping in their beds. The bodies were discovered by the only family member left alive – the oldest son Butch DeFeo. What really happened that night in Amityville? Who murdered the DeFeo family and why? What caused the strange events in the house near the sea? Parapsychologists and psychics descend on the house to investigate claims of levitating objects and demonic possession in an attempt to explain why, 50 years later, this house is still a source of nightmares.

In 1968, an 8-year-old girl is abducted and raped. The Los Angeles police were just moments from catching her attacker, but he eludes them and escapes to New York where he kills a young woman. This is the beginning of a monstrous killing spree of young girls and women. When police discover who is behind these horrific murders, they are shocked to find it's a handsome, charming photographer. With a string of murders already behind him, incredibly, Rodney Alcala is chosen to appear on the national game show, "The Dating Game." What happens next makes Rodney Alcala one of the most horrific serial killers in US history.

In 1968, an 8-year-old girl is abducted and raped. The Los Angeles police were just moments from catching her attacker, but he eludes them and escapes to New York where he kills a young woman. This is the beginning of a monstrous killing spree of young girls and women. When police discover who is behind these horrific murders, they are shocked to find it's a handsome, charming photographer. With a string of murders already behind him, incredibly, Rodney Alcala is chosen to appear on the national game show, "The Dating Game." What happens next makes Rodney Alcala one of the most horrific serial killers in US history.

He was a family man, living in a New Jersey suburb with his wife and three kids. But unbeknownst to his neighbors, Richard Kuklinski held a dark secret: he was the "Iceman" – a cold-blooded killer who was part-time mob hitman for hire, and full-time psychopath. This intimidating, oversized killer managed to evade the police with ease for years. That is, until a few smart investigators started connecting the dots between seemingly unrelated murders and a mystery man known as "Big Rich."

He was a family man, living in a New Jersey suburb with his wife and three kids. But unbeknownst to his neighbors, Richard Kuklinski held a dark secret: he was the "Iceman" – a cold-blooded killer who was part-time mob hitman for hire, and full-time psychopath. This intimidating, oversized killer managed to evade the police with ease for years. That is, until a few smart investigators started connecting the dots between seemingly unrelated murders and a mystery man known as "Big Rich."

A string of horrifying fires plagues California in the Eighties and Nineties, one of them fatally trapping four people inside. Are these raging infernos accidental or is someone setting them deliberately? Years of meticulous investigation leads law enforcement to uncover a wave of terrifying fires set by a man some call the most prolific arsonist of the Twentieth century, who turns out to be none other than renowned fire investigator Captain John Orr. In a game of cat and mouse, colleagues discover dark secrets behind the man who thrived on the chaos of igniting the fires he was supposed to be fighting.

A string of horrifying fires plagues California in the Eighties and Nineties, one of them fatally trapping four people inside. Are these raging infernos accidental or is someone setting them deliberately? Years of meticulous investigation leads law enforcement to uncover a wave of terrifying fires set by a man some call the most prolific arsonist of the Twentieth century, who turns out to be none other than renowned fire investigator Captain John Orr. In a game of cat and mouse, colleagues discover dark secrets behind the man who thrived on the chaos of igniting the fires he was supposed to be fighting.

From 1987 to 1992, young women were abducted and murdered north of the U.S.-Canadian border. A tip led cops to an unlikely suspect: a blond, blue-eyed accountant who lived with his wife in a pink house in the suburbs.

From 1987 to 1992, young women were abducted and murdered north of the U.S.-Canadian border. A tip led cops to an unlikely suspect: a blond, blue-eyed accountant who lived with his wife in a pink house in the suburbs.

When college-aged women go missing, the investigation leads authorities to a local star athlete.

When college-aged women go missing, the investigation leads authorities to a local star athlete.

Sammy "The Bull" Gravano was the right-hand man to mafia kingpin, John Gotti. He carried out multiple murders. After his arrest, he broke the sacred oath of silence and cut a deal with the government, testifying against his former boss.

Sammy "The Bull" Gravano was the right-hand man to mafia kingpin, John Gotti. He carried out multiple murders. After his arrest, he broke the sacred oath of silence and cut a deal with the government, testifying against his former boss.

In the fall of 1977, bodies of young women begin piling up in LA. Almost all of the victims are nude, discarded on hillsides showing signs of torture. It is nearly a year before two murders 1200 miles away uncover the Hillside Stranglers.

In the fall of 1977, bodies of young women begin piling up in LA. Almost all of the victims are nude, discarded on hillsides showing signs of torture. It is nearly a year before two murders 1200 miles away uncover the Hillside Stranglers.

Samantha Koenig was closing shop in Anchorage, Alaska, when a man known in the community as a business owner and caring father, approaches. After kidnapping Samantha, an intense manhunt took authorities on a cross country investigation.

Samantha Koenig was closing shop in Anchorage, Alaska, when a man known in the community as a business owner and caring father, approaches. After kidnapping Samantha, an intense manhunt took authorities on a cross country investigation.

John Gotti's expensive suits and swagger earned him the nickname Dapper Don. But, in reality, he was a man to be feared. A ruthless, dangerous mafia gangster who ordered hits on his enemies, his friends, and anyone who crossed him.

John Gotti's expensive suits and swagger earned him the nickname Dapper Don. But, in reality, he was a man to be feared. A ruthless, dangerous mafia gangster who ordered hits on his enemies, his friends, and anyone who crossed him.

A killer stalks California; the clues are scarce, until one victim gets away.

A killer stalks California; the clues are scarce, until one victim gets away.

In the mid 1980s, Kansas City women start to vanish; they all share one thing in common, an odd connection to the same man who calls himself "The Slave Master"; police must be just as wily if they want to bring down this serial killing sadist.

In the mid 1980s, Kansas City women start to vanish; they all share one thing in common, an odd connection to the same man who calls himself "The Slave Master"; police must be just as wily if they want to bring down this serial killing sadist.

Identical twins aren't always alike, especially when one might be a killer.

Someone snatches a student from her college campus in Indiana, while a second missing girl turns up dead months later. When terrified girls report a man trying to lure them into his van, police wonder if he is the real killer until one man confesses.

Richard Francis Cottingham (born November 25, 1946) is a convicted serial killer and rapist who murdered at least eighteen young women and girls in New York and New Jersey between 1967 and 1980. He was nicknamed as: The New York Ripper, The Torso Killer and The Times Square Killer. Cottingham was arrested on May 22, 1980 and convicted of numerous murders. He was sentenced to multiple life sentences in prison. In 2009, decades after his first five murder convictions, Cottingham told a journalist that he had committed at least 80 to 100 "perfect murders" of women in various regions of the United States.

Richard Francis Cottingham (born November 25, 1946) is a convicted serial killer and rapist who murdered at least eighteen young women and girls in New York and New Jersey between 1967 and 1980. He was nicknamed as: The New York Ripper, The Torso Killer and The Times Square Killer. Cottingham was arrested on May 22, 1980 and convicted of numerous murders. He was sentenced to multiple life sentences in prison. In 2009, decades after his first five murder convictions, Cottingham told a journalist that he had committed at least 80 to 100 "perfect murders" of women in various regions of the United States.

Cops wonder if a series of deaths means a black widow is spinning her web.

Nurse Judy Buenoano survives a string of unimaginable tragedies, including two house fires, a mysterious canoe accident, and the loss of her husband, boyfriend, and child. It is discussed whether Judy is just a magnet for bad luck or if something far more sinister is at play.

Keith Hunter Jesperson (born April 6, 1955) is a Canadian-American serial killer who murdered at least eight women in the United States during the early 1990s. He was known as the "Happy Face Killer" because he drew "smiley faces" on his numerous letters to the media and authorities. Many of his victims were sex workers and transients who had no personal connection to him. Strangulation was Jesperson's preferred method of murdering, the same method he often used to kill animals as a child. He was eventually arrested and convicted. He is serving multiple life sentences in prison, with no possibility of parole.

Keith Hunter Jesperson (born April 6, 1955) is a Canadian-American serial killer who murdered at least eight women in the United States during the early 1990s. He was known as the "Happy Face Killer" because he drew "smiley faces" on his numerous letters to the media and authorities. Many of his victims were sex workers and transients who had no personal connection to him. Strangulation was Jesperson's preferred method of murdering, the same method he often used to kill animals as a child. He was eventually arrested and convicted. He is serving multiple life sentences in prison, with no possibility of parole.

Anthony Sowell appears to be a helpful member of his Cleveland neighborhood, and he uses those charms to lure unsuspecting women into his modest house. However, once inside, he turns into the devil and leaves a twisted trail of torture, rape and murder.

In mid-90s Miami, a crew of bodybuilders known as the Sun Gym Gang preys on the rich to rob them blind. As their greed grows, they turn to murder, resulting in one of the goriest crime scenes in Florida history.

In the early 90s, sadistic drug kingpin Clarence Preacher Heatley rules New York City. He rakes in millions during the crack epidemic, murdering anyone who gets in his way. After a 12-year-old boy is killed, the Feds try to take him down.

David Matusiewicz, Christine Belford, and their four children live the American Dream. But when David's parents move in, his family's need for control over the children leads to allegations of abuse, a 19-month kidnapping, and ultimately, a brutal murder.

Marjorie Diehl-Armstrong starts her life as a bright young woman with a promising future. However, her true colors soon show as she goes down a sinister path of manipulation, bank robbery and multiple gruesome murders.

A shooting nearly destroys a boxer's career, but trouble soon finds him again when a second shooting claims his wife. Is it suicide — or murder?

Starting in the late 1990s, a killer torments young women and his own family in the Pacific Northwest.

In 1994 a violent serial killer hunts elderly women in a gated California community. A family member of the murderer realizes that the culprit is close to home, as the police hurry to stop her before she can kill again.