A tip from a missing persons network helps identify the body of a John Doe murder victim, leading investigators to unravel a dark tale of betrayal.

In North Port, Fla., police receive a call reporting that a young mother has gone missing; in an effort to find her, detectives follow a trail of incoming 911 calls that reveal a heartbreaking story more horrific than they could have ever imagined.

In Rison, Ark., a young woman is abducted from her home in the middle of the night; when investigators dig up her body in the woods, they uncover an appalling murder plot that led to the victim's gruesome demise.

When a young woman disappears after a visit to the mall, and investigators discover from store surveillance footage that she has been abducted, she is found dead in the woods.

In the coastal town of Leland, N.C., a missing woman is found dead in a swamp; as detectives speak with the victim's friends and family, they begin to unravel the truth behind a horrifying murder.

In Ohio, a woman is found stabbed to death in her kitchen after she fails to show up for work; her sister is able to help detectives solve the case after a family heirloom is discovered during the investigation.

Sharon Ord and her family leave Scranton, Pa., to start a new life in Florida; then one of them disappears, turning their dream of a new life into a nightmare.

In Stamping Ground, Ky., a young woman's dead body is found late at night by her brother and father; when detectives learn the victim was pregnant, they consider it a motive for murder and begin a homicide investigation.

In Dayton, Ohio, a young mother goes missing after attending a party, and her identical twin becomes convinced there is something deeply sinister afoot.

On the Northern Cheyenne Indian Reservation, a young mother goes missing after the Fourth of July; when her body is discovered in the woods, the victim's family dig through the memories of their loved one to provide investigators with critical clues.

Billy Carter raises daughters Crystal and Misty in the Great Smoky Mountains of North Carolina; after a body is found on the scenic Blue Ridge Parkway, this family's piece of paradise becomes a nightmare they relive again and again.

In the suburbs of Atlanta, Ga., a pregnant woman and her fiancé are kidnapped on the night before their baby shower and the fiancé's family receives ransom calls that same night.

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.

In this eight-episode series, viewers hear directly from detectives who investigated cases that haunt them to this day. These true-crime stories -- from mysterious vanishings to twisted family murders -- are the "unforgettable cases that disrupt law and order, and keep authorities up at night," says Investigation Discovery.

"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.

Chilling scenarios unfold in this true-crime series, which tells actual stories of people who shared their lives with loved ones who became killers. Each hourlong episode puts viewers in the shoes of the loved one, who first notices that something is amiss, interprets the puzzling signs and clues, and eventually comes face-to-face with the horrible truth: that the person has a very dark side. Exclusive interviews and firsthand accounts of the critical moments leading up to the vicious acts showcase devastating, often undiscussed consequences on the people who have nurtured, loved and raised a murderer.