Sex trafficking has evolved in the 21st century to focus heavily on social media and financial mobile applications. And despite efforts to stop it, it's increasing globally.

In 2010, Lawrence Ray, a 50-year-old ex-con, formed a sex cult at his daughter's dorm room at Sarah Lawrence College in New York and humiliated, tortured and trafficked members for his pleasure and monetary gain.

On November 13, 1974, DeFeo killed his family in Amityville. Although he confessed, his motives remain unclear.

Joseph Augustus Zarelli was found in a cardboard box in 1957.

Strange texts follow after a single mom disappears. Years later, investigators unravel web of deceit, leading to murderer's conviction.

Jana Monroe, one of the FBI's first female agents with the Behavioral Science Unit, on what it was like interviewing serial killers.

In 1957, the notorious Wisconsin killer was arrested for murdering two women and digging up corpses. What influenced his gruesome behavior?

In 2010 the Internet provocateur launched IsAnyoneUp.com, the first 'revenge porn' website, where users could post intimate images of other people without their consent. Where is Hunter Moore now?

Judges can find anyone in contempt if they are disrespectful.

Authorities say Allen incriminated himself 61 times.

Law enforcement agencies are ramping up use of artificial intelligence to help solve crimes, but experts warn the technology is still in its infancy and should only be used to augment traditional investigative methods.

In 2006, four sex workers were found dumped in a ditch near Atlantic City's border. The serial killer has yet to be identified.

A look at milestones in police use of DNA evidence.

Explaining why criminals receive multiple life sentences.

Was bullying during his early years to blame for Joel Rifkin becoming one of the most prolific serial killers in New York history?

During the 1990s and early 2000s, more than 30 women were targeted by serial killers, including Derrick Todd Lee, in the Baton Rouge area.

The reign of the bodybuilding world's most famous couple, Sally and Ray McNeil, ended after Sally murdered Ray with a shotgun in 1995.

We speak with Deborah Marion, mother of murdered NBA star Lorenzen Wright and Darren Goods, a lead investigator in Wright's homicide case.

In 2003, Steven Mack, a homicide detective with the Huntington Beach Police Department, took a leading role in retrying a twice-overturned murder case against Rodney Alcala. His efforts led to the uncovering of a prolific serial killer.

The British-American anti-virus software pioneer was found hanging in his cell in a Spanish prison hours after a court ruled that he would need to return to the U.S. to face tax evasion charges. But his inner circle has doubts about the manner of his death.

Millionaire Jim Sullivan's marriage to Black socialite Lita McClinton ended with Lita’s murder. Deb Miller Landau book delves into Lita's impact on her community, Jim’s fall, and racial dynamics.

After Tom Kolman's mysterious death, Kingston, New York dentist Gilberto Nunez, who pretended he was with the CIA and was having an affair with Kolman's wife, was tried for his murder.

Detective Lindsey Wade on the experience of solving the 1986 cold case murder of 13-year-old Jennifer Bastian from Tacoma, Washington.

Kaitlin Armstrong killed pro cyclist Anna Moriah Wilson, who was having a secret relationship with Armstrong's boyfriend, pro cyclist Colin Strickland and is currently serving 90 years in prison.

Two years after the Jonestown Massacre, ex-members of the cult, Al, Jeannie and Daphene Mills, were murdered. The killer was never caught.