Amanda Antoni's husband finds her body in their basement with blood everywhere. The scene confounds police: Was it foul play — or a tragic accident?

Sigrid Stevenson's chilling murder on the stage of a locked campus theater still haunts a New Jersey college as new theories about her killer emerge.

When an aristocrat and his entire family disappear, the authorities unearth something horrifying.

After rushing from his home, Rey Rivera disappears. Days later, his car is found — and a strange sight at a historic hotel triggers a baffling mystery.

Twenty-year old Josh Guimond leaves a college party without a word and is never seen again. Two decades later, his loved ones just want answers.

After checking in at a luxury hotel with no ID or credit card, a woman dies from a gunshot. Years later, her identity — and her death — remain a mystery.

Patrice Endres abruptly vanishes from the salon she owned within a 13-minute window of time. Exactly 600 days later, her case takes a shocking turn.

Given a furlough to go Christmas shopping in 1973, a convicted killer escapes. Police have come close to apprehending him but believe he's still at large.

After a teen finds an embalmed head in the woods, investigators uncover a possible connection to a black-market organ trade as they try to ID the victim.

Two friends were shot dead at a busy park on a June day, but the killer escaped unseen. Grieving families are on a hunt for clues about the brazen crime.

Alonzo Brooks vanishes after a party. His body is found a month later. Many believe that his unsolved death is a hate crime.

Police find the body of former White House aide Jack Wheeler in a landfill. Security footage captures strange events in the days leading up to his death.

In May and August 1989, two toddlers vanished from the same New York City park. A search turned up nothing — but their families haven't given up hope.

For decades, a wave of cattle mutilations executed with near-surgical precision has plagued the US. Are extraterrestrials behind these gruesome acts?

Lena Chapin claims on tape that her mother killed her stepfather. Several years later, she's issued a subpoena to testify in court — then disappears.

On an icy night, police find JoAnn Romain's abandoned car and assume she drowned in a nearby lake by suicide. But her family suspects foul play.

Amid eerie sightings of a tall, winged humanoid creature with red eyes, paranormal investigators explore the Mothman's seeming link to major disasters.

Tiffany Valiante, a promising young athlete, is struck by a train four miles from home. But was her death a suicide or something more sinister?

A beloved father is brutally mutilated, but his presumed killer, a woman he knew from high school, escapes without a trace.

Buffalo Jim Barrier's larger-than-life presence in Las Vegas rankled the mob. Could that explain his untimely death under suspicious circumstances?

Residents of Berkshire County, Massachusetts, recall their baffling, terrifying experiences with a UFO on the night of September 1, 1969.

In 1947, an unidentified flying object crashed near Roswell, NM. Was it a spy balloon or an alien encounter? UFO experts unravel the iconic mystery.

A massive earthquake and tsunami devastated Japan in March 2011. Residents share stories of the spirits they encountered in the wake of the disaster.

Over 300 residents of western Michigan report seeing unearthly lights on the night of March 8th, 1994. Decades later, the event remains unexplained.

Bigfoot, orbs, UFOs, poltergeists and skin-walkers. For these Navajo Nation rangers, paranormal activity is just part of the job.