Police investigate the mysterious disappearance and possible murder of a 20-year-old single mother; detectives suspect the witnesses to a fatal shooting know more than they are saying; Dallas detectives embark on a manhunt across three states.

When a homeless man is gunned down on the sidewalk, Mobile detectives discover a petty motive.

In Tulsa, a vicious hammer attack leaves two young men clinging to life. Detectives race to catch the suspect before he strikes again. In Atlanta, detectives discover a selfless act performed by their victim led to his murder.

A police detective must determine if the person who gunned down a New Orleans teenager is a friend or a foe; the employees of an executed businessman may prove a motive for the crime.

A running street battle in Tulsa, Okla., results in the death of a young father; an Atlanta man is shot in the back when he defends his mother's honor.

A suburban teen is killed in a robbery gone bad, prompting a Minneapolis police detective to determine which of the victim's friends may have double-crossed him.

In Miami, police attempt to find the killer of a good Samaritan who intervened in a robbery; a homeless woman may have information on the crime.

After one of their own is executed in cold blood, New Orleans homicide detectives learn their suspect may have killed before.

Atlanta detectives try to find a lead from a roommate involved with suspect in shooting; Tulsa man shot in face and Detective Justin Ritter must learn if shooter acted alone or if it was prison gang hit; man found dead in notorious Atlanta drug den.

New Orleans police detectives prepare to face a potentially armed suspect believed to be hiding in his apartment.

Detectives uncover a vengeful motive while investigating a shootout in an Atlanta rap studio that left two men dead.

A Tulsa, Okla., man gunned down in broad daylight; a New Orleans man shot eight times in his own home after a text message lands in the hands of a killer.

When a stray bullet kills a retired preschool teacher, Atlanta detectives need a witness to break the code of silence surrounding the crime.

A New Orleans detective questions a witness' claim that a man found shot to death in his bedroom committed suicide.

Tulsa, Okla., police detectives scour the city for a witness who might hold the key to solving a back-alley homicide.

When a new father is brutally gunned down, a police detective's only lead in the case is something the killer left behind.

A night out leaves an innocent man dead. When solid leads hit dead ends, detectives discover a motive they never expected.

A young Atlanta man is shot and left to die in the bushes; a police detective's main clue in the case is a mysterious white town car.

A Tulsa, Okla., woman goes on the run after the murder of her boyfriend; an Army veteran gunned down after helping a homeless man in Atlanta.

When a man is gunned down protecting his wife, police detectives hope his ex-wife can reveal who may have wanted him killed.

A Tulsa, Okla., police detective cuts through conflicting stories in the case of a man who was shot and run over by a car; a gunman opens fire outside an Atlanta nightclub, killing one man and leaving another clinging to life.

Detective Rayell Johnson investigates the shooting death of an elderly New Orleans man found dead outside his home, while Atlanta Detective Kevin Leonpacher must ID the young man and woman caught on a store camera committing a murder in broad daylight.

When an argument at a Tulsa, Okla., bar ends with the fatal shooting of a young social activist, police search for answers in a divided community.

When a turf war leaves an elderly woman dead, Atlanta homicide detectives turn up the heat to prevent more bloodshed.

The investigation into the execution of a Somali girl leads Minneapolis police to uncover a secret relationship that may have turned deadly; a shooter kills a beloved son when a house party in Tulsa, Okla., gets out of control.

New Orleans homicide detectives work the stabbing death of an infamous local criminal; a squabble among friends leaves a woman brutally murdered in a Minneapolis bus station.

When a young man from Tulsa., Okla., is found shot dead in his van, homicide detectives retrace his final hours and get caught up in a web of lies.

In Atlanta, a brash murder in front of an elementary school turns up a familiar name.

After a young woman has a deadly premonition, the New Orleans homicide team learns her killer may have killed before.

Tulsa, Okla., police detectives scour the city for a witness who might hold the key to solving a back-alley homicide.