Season 12

When a young woman is found shot to death, it's hard to imagine why anyone would have harmed her; as investigators uncover potential suspects, they're challenged by violent backgrounds, mental health issues, drug problems, and obsessive behavior.

When a nursing student disappears, suspicion immediately falls on her boyfriend and the other woman in his life; police struggle to pinpoint a suspect until a guilty conscience leads them to her body -- and her killer.

On June 26, 2008, 31-year-old scientist Kerri Harris' life is cut short by a vicious attack in her office just outside Atlanta, GA. As detectives struggle to identify a suspect, they realize evil lurks just beneath the surface.

When a former drug addict disappears, police worry she may have relapsed. Then, her body is found in her abandoned car and investigators suspect foul play; police chase a killer who has a very dark past.

When a loving father and husband is beaten to death in his own home, shocking secrets of jealously, embezzlement and scorned lovers soon begin to surface. As detectives search for the homicidal intruders, they uncover suspects much closer to home.

A woman is found dead by the railroad tracks in New Jersey; the victim's boyfriend is the prime suspect until police discover a secret relationship she had with another man.

Engaged to the man of her dreams, a young mother seems to have it all until her future takes a horrific turn, and she is gunned down in a park; detectives must untangle a complicated conspiracy to find the answers they seek.

When a young woman disappears after a weekend with her boyfriend, her worried family wonders what could have happened; the boyfriend claims she left with a male friend, but the friend denies it; someone is lying, and detectives must find the truth.

After a woman goes missing, police are reluctant to jump on the case because of her past. When they begin investigating the circumstances surrounding her disappearance, detectives find alarming evidence, leading to an even more disturbing crime.

A young man leaves his troubled life in the city behind for a peaceful desert town where he finds love among the desert heat. When he is brutally gunned down inside his own home, police wonder if his past has come back to haunt him.

A community is shocked when the body of a woman, with a history of addiction, packed in a suitcase washes ashore along San Francisco Bay. Investigators wonder whether it stemmed from an overdose, a drug deal gone bad or something more sinister.

After a woman is found dead in a car, detectives quickly begin an investigation. What begins as a clear-cut case soon takes a turn as new leads complicate the story.

When a young college student vanishes near campus, police move quickly to locate her. As the mystery unfolds, reinforcements are called in, and after many suspects, investigators finally uncover the truth.

After a young woman is found dead on the side of a Nashville highway, questions swirl about who could have killed her.

When a woman is found shot to death in her bedroom, detectives immediately set their sights on her ex, with a long history of abuse. As they dig deeper, dark secrets are revealed and the answer to who killed her hits even closer to home.

After a corrections officer is found dead in his apartment, police wonder if a former inmate got revenge on him. It's soon clear that the murder may not be related to his job, once police uncover their victim's part in a dangerous love triangle.

A husband and father of two is found bleeding out on the floor. As the investigation unfolds, it reveals a trail of lies and infidelity, prompting investigators to ask whether this was a tragic accident or a jealousy-fueled murder.

A couple escape the city for a slower-paced life, but it all ends in tragedy when one of them disappears. Stunning clues and mysterious circumstances lead investigators to a surprising suspect and one final question.

After autopsies show signs of arson and other injuries, police are left to determine if a woman, her mother and young daughter were targeted in an attack.

When a young mother is shot on Halloween night, detectives start by investigating her relationships to determine if a ghost from her past had come back to haunt her, or if her current relationship is more sinister than it seems.

After a driver is found dead in the cab of his semitruck, investigators are determined to solve the case. The investigation reaches a stalemate, then a tip reveals a killer whose greed outweighs the bonds of love and family.

When police find a woman dead in a motel bathtub, they suspect an overdose until they notice bruises on her neck. As detectives hunt for the unknown man who rented the room, they find security footage that leads them right to their killer.

An anonymous 911 call leads police to a woman who has been shot in her bedroom and there are signs of a struggle throughout the house. They initially suspect a robbery gone wrong, but then uncover secrets that suggest a closer connection to the killer.

When a father and daughter are found murdered in their home, police are left with more questions than answers. But as detectives dig deeper into the case, they uncover a chilling motive that questions a mother's instincts - and destroys a family.

When a young mother is shot inside her car, it's hard to imagine why anyone would have harmed her. As investigators uncover potential suspects, they're challenged by layers of lies, differing accounts, unwilling witnesses, and possessive behavior.

When a devoted husband and father is found stabbed in a motel room, police speculate that it was an illicit drug deal that went south; as they investigate, they find that the gruesome ambush may have had a more sinister motive.

Two Americans fall madly in love abroad, but back home, tragedy strikes when one of them is found dead in their home; the truth blurs the line between perpetrator and victim.

When a man is shot while arguing with his girlfriend, police wonder if she was responsible; they learn two hooded men were the ones who fired; the search for who's behind the killing will reveal the secrets that led to the man's last breath.