Serial killers are not born; it’s a mix of environmental factors that activate the evil in us. In her own words, “You get a combination of factors, environmental and intrinsic, that create a very violent person.

But considering the limitations of forensic science, many believe this is an undercount. Police only make an arrest — or “clear” a case, in justice jargon — in about 60 percent of all homicides. The other 5,000 end without closure. In other words, murderers have a 40 percent chance of getting away with murder.

Most serial killers seek dominance over their victims. They love to see the fear in their victims’ eyes and consider murder the ultimate form of dominance over a human being. That’s why serial killers look for people who are vulnerable, allowing them to achieve that feeling of superiority.

You will walk past 36 murderers in your lifetime. On average, you will walk past 36 murderers in your lifetime.

A 2005 study in the Journal of Police and Criminal Psychology revealed that the prevalence of childhood-sexual abuse among serial killers was 26 percent, while 36 percent had experienced physical abuse and 50 percent had been psychologically abused as children.

50 serial killers

These stars aren’t just talented and smart—they’re actually geniuses, and we’re giving them props on Smart is Cool Day. In addition to gracing the big and small screens, they’ve earned a membership in Mensa, an international society for people with an IQ in the top 2 percent of the general population.