What is evil—and how do we measure it? Is it more evil to abduct and torture a stranger for days before ultimately letting them go, or to fatally shoot a spouse in a fit of jealous rage? We speak to clinical psychologist Dr. Gary Bucato, co-author of the new book, 'The New Evil,' about how he determined what acts are more evil than others and why serial killers aren't all categorized the same way.

There's a new epidemic coming to light in Alaska—and in other areas around the U.S.—where hundreds, and possibly thousands, of Native American women are turning up missing or murdered. But legislative, funding and awareness-raising efforts are under way, and the issue is getting some political traction from the #MeToo movement. .

Serial killer Richard Ramirez, otherwise known as 'The Night Stalker,' terrorized California in the mid-1980s with a series of rapes and murders. A number of women who survived his attacks mentioned his rotten teeth, among other details, helping police create a profile of the suspect.

The United States may have churned out the highest number of serial killers in the world over the years, but it certainly doesn't hold exclusive rights on brutal murders. Learn about some international serial killers and how their respective countries handled their crimes.

After the 2005 disappearance of Teresa Halbach, 16-year-old Brendan Dassey confessed to police that he and his uncle, Steven Avery, raped and murdered her. But Dassey later recanted his confession, suggesting that he'd been coerced into telling the police what they wanted to hear. The jury didn't buy it and sentenced him to life in prison.

A&E True Crime looks at some of the most famous cases of abused people fighting back, sometimes with deadly results.