Thirty-nine men and women, all dressed in identical clothing, were found dead due to suicide in 1997. Here's what to know about the Heaven's Gate cult.
It's been years since the rise of the internet legend Slenderman, but we still remember the terrifying Slenderman stabbing that drew in two teenage girls.
The Branch Davidians are an apocalyptic religious sect that broke off from the Seventh Day Adventist Church. Here's what we know about leader David Koresh.