A&E True Crime spoke with Michael Santos, who spent 25 years in prison, about what it was like to enter a world so dependent on technology after being incarcerated for so long.

People are trading bitcoin for goods and services on the illegal marketplaces of the dark web, where the easy, instant flow of the cyptocurrency allows users to tap into their darkest natures--all from the anonymous comfort of their home computers.

German serial killer nurse Niels Hoegel is suspected of killing more than 300 patients at two hospitals in Germany. Beatrice Yorker, an expert in serial killings in health arenas, tells us how killers in medical professions often get away with the crime.

Debates around and other little-known facts about the leader of the Branch Davidians, David Koresh, and the Waco siege.

Quite often it is only in hindsight that the friends and family of a mass-shooting perpetrator realize that the bloodbath was actually the climax of a series of foretelling clues from an angry, violent, paranoid, withdrawn person, who happens to have a  newfound fixation with guns. Such devastating epiphanies beg the question: Can we predict tomorrow's mass shooter?

The story of a California couple, Louise and David Turpin, charged with abusing their 13 children, is only the latest high-profile case involving parents accused of horrific acts.

Although not as well known or remembered for their horrific deeds as serial killers are, serial rapists exert control through terrifying means.

Read an excerpt of the true-crime book "The Man From the Train: The Solving of a Century-Old Serial Killer Mystery" of the murder of the unorthodox Schultz family of Houston Heights, Texas.

Thomas Hargrove of the Murder Accountability Project talks about the 2,000 or so serial killers he believes are prowling U.S. streets now.

A&E True Crime spoke with Dr. Gail Saltz, clinical associate professor of psychiatry, about why the serial killer was so well-behaved after he was locked up.