A gruesome murder puzzles police; a cryptic message is left behind at the crime scene, but the identity of the killer remains a mystery; promises are broken, and old secrets emerge, breathing new life into the investigation.

In Allentown, Pa., a serial killer preys on women in the middle of the night; when one woman refuses to be his next victim, the killer goes on a relentless tirade that ends in his own demise.

In Bend, Ore., Halloween night ends with a young woman's disappearance; suspicion of foul play runs deep, but her whereabouts remain a mystery; over time, secrets begin to emerge and lead investigators to the least likely of suspects.

In Great Falls, Mont., police are on high alert after Morris Davis and Suzette Pritchard are brutally murdered just one year apart; one tip will change everything as the police hunt for a killer.

Working the graveyard shift, a convenience store clerk is on edge after a string of murders are committed within blocks of her store; soon, her worst nightmare becomes a reality when she comes face to face with a serial killer.

A woman's attempt to flee a troubled relationship leads to her demise; police discover a haunting message left behind, but the case goes cold for years until a prime suspect's macabre desire for blood is revealed.

A young woman with a promising future vanishes from her apartment in the middle of the night; family and friends search desperately for any sign of her, but the truth will only come to light after a grisly crime is committed miles away.

In Baltimore, a predator stalks young women and strikes when they are alone at night; however, one of the killer's victims will turn out to be his worst enemy.

A young college student vanishes; later, a shocking discovery is made, and townspeople begin to question those they once believed were innocent; before long, the truth rises from the dead of night.

In Baton Rouge, La., defense attorney Chiquita Tate is murdered while alone in her office at night; police quickly zero in on a prime suspect until a twisted conspiracy from Tate's past comes to light.

After finishing a midnight shift at a local factory, Fred Matting is murdered in his own driveway; his once peaceful neighborhood turns into a living hell as residents fear that a vicious killer is lying in wait for them.

Two young mothers living hundreds of miles apart vanish under eerily similar circumstances; years pass without a single lead in either case until a Missouri police officer's routine house call uncovers an unlikely suspect.

Hundreds of homicide cases in any given year can shake even the staunchest cities and police departments to the core. The statistics, however, don't paint the real stories and the effect that lingers -- through the pain endured by victims' loved ones, the community impact, and the memories that detectives will never forget. "Homicide City" explores unforgettable murder cases from major American cities, investigations that had law enforcement banding together across metropolitan landscapes in a sequence of manhunts. Each story is told by veteran homicide detectives, local reporters, and the victims' families.

Once dubbed "Wonderland" because of its immense summer beauty and grandeur, the rolling mountains and deep forests of the Pacific Northwest become a haven for a series of murders. Using stylized re-enactments and interviews with law enforcement personnel and family and friends of victims, episodes focus on a team of dedicated Portland, Ore., homicide investigators who seek answers to mysterious, disturbing murder cases. In the premiere, Det. Molly Daul realizes she is dealing with a sexual predator, whose chilling confession remains with Molly to this day. The killer then turns his sights on her, raising the stakes even higher.

"Accident, Murder, or Suicide" investigates the deaths that are just a little bit too mysterious. It explores the unbelievable true stories in this hourlong program. Each episode retraces the investigation from the start to the end. Investigators take viewers through the twists, turns, and unexpected surprises as they dissect the red flags, show evidence, and point out the strange behavior that puts everything into question.

"Betrayed" reveals chilling stories of chasing the American dream and how the veneer can dramatically crumble, ending in murder at the hands of a trusted family member, co-worker, lover, or friend. The cases of deception are told through the lens of the fictionalized, first-person perspectives of the victims. As investigators, family, and friends peel back the layers and facts of each case, the otherworldly narrator already knows where the trail ends. The narrator guides viewers through various relationships, raising suspicions about who will commit the ultimate betrayal.