In the spring of 2009, a short-lived spree of attacks against women in Boston and Rhode Island had the Eastern Seaboard on edge. But when a suspect was finally identified, the revelation was almost too bizarre to believe: a clean-cut, promising medical student with a seemingly perfect home life. As investigators dug deeper, they uncovered a dual existence darker and more calculated than anyone who knew him could have possibly imagined. These are the crimes of the Craigslist Killer, otherwise known as Philip Markoff.

In the summer of 1986, two young girls vanished mere months apart, both while out riding their bikes in Tacoma, Washington. Despite exhaustive efforts, both cases went cold, until decades later, when a surprising breakthrough revived the investigation. With new forensic tools and a fresh set of eyes, detectives began to piece together a puzzle that had haunted the community for years, finally finding answers over 30 years later. These are the murders of Michella Welch and Jenni Bastian, otherwise known as the Tacoma Girls.

In July of 2025, a couple and their two young daughters were hiking at the Devil's Den State Park in Arkansas after recently relocating to the area. But while on the trail, a strange man approached the family, stabbing and murdering the parents. Within days, someone was arrested for the slayings, and his identity would shock the nation. These are the murders of Clint and Cristen Brink, also known as the Devil's Den Murders.