Katelyn Markham // 531

In August of 2011, a 21-year-old art student suddenly vanished from her Ohio townhouse. Her purse, her car —even her beloved dog—were all left behind. And with no signs of struggle and no clear explanation, the case baffled investigators and shook her community. For nearly two years, her disappearance was a haunting mystery… until a discovery miles away across state lines changed everything. This is the murder of Katelyn Markham.

In August of 1973, a 22-year-old woman was beginning her graduate degree in psychology at the same Missouri university when she was brutally murdered in her apartment. Originally, police believed the crime was committed by a woman. Or, a professor she may have been seeing on campus. Now, 52 years later, even more curious potential suspects have come into play, as a whole new investigation is underway. This is the murder of Tess Hilt.

In July of 2023, a beloved elementary school teacher took a walk through her Maryland neighborhood, just as she did every evening. But this time, she never came home. Within days, her disappearance sparked a massive search effort involving local authorities and concerned volunteers alike. As the weeks wore on, eerie details surfaced, including a photograph of the murder suspect as he was disposing of her remains. This is the murder of Mariame Toure Sylla.

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.

In March of 2024, two women set off on a short drive through the rural backroads of Oklahoma, but they never made it to their destination. Hours later, their car was found abandoned by the side of the road, but suspiciously, along with signs of a struggle. As the search for them intensified, authorities uncovered a trail marked by custody battles, a religious cult, and secrets buried deep in a small-town community, which would ultimately lead to five arrests. These are the murders of Veronica Butler and Jilian Kelley.

In the 1980s and ’90s, a deeply disturbed man from New Jersey drifted from town to town, hiding behind a soft-spoken voice and a childlike demeanor. Seemingly tormented by delusions, and obsessed with revenge, he harbored gruesome secrets. By the time investigators connected him to the 1986 disappearance of six-year-old Michele Dorr, and later, the baffling vanishing of Harvard graduate Laura Houghteling, it was clear: this man wasn’t just strange... He was deadly. And he may have left behind more victims than anyone ever realized. This is the story of Hadden Clark, also known, as the Cannibal Gardener.

In July of 1986, a 19-year-old man was found hanging from a tree near his Maryland home. Authorities swiftly ruled it a suicide, but those closest to him questioned everything about the scene; from the small tree, which could barely support his weight, to the lack of an autopsy, to the suspicious friends who seemed to vanish in the wake of his sudden death. Years later, his mother received a suspicious envelope on her doorstep, and new evidence would challenge the original ruling. This is the death of Keith Warren.

In July of 1995, a 24-year-old woman in Alaska headed out on a date with a man she had only recently met. She was last seen at a crowded summer fair in the forest, surrounded by tourists - but by the time the sun rose the next morning, she was gone. What followed was a desperate search in the unforgiving Alaska wilderness, and eerie silence from her date, which only deepened the mystery. This is the disappearance of Erin Gilbert.