The First 48

In Tucson, a grandfather is shot after answering a knock at his front door. The suspect's getaway car crashes a few blocks from the crime scene and the suspect flees.

In Memphis, Sgt. Debo Carson and her team investigate the murder of a man shot dead outside of his house.

In Memphis Sgt. Eric Freeman and the homicide team investigate the high-profile murder of a University of Memphis college football player.

In Dallas, Detectives Scott Sayers and Ken Penrod are investigating a home invasion that left a young man dead.

In Dallas, Det. Robert Arredondo and his team investigate the murder of a 22-year-old man tied up and shot along with two of his friends during a robbery.

In Cincinnati, Detectives Keith Witherell and Bill Hilbert attempt to crack the code of silence.

In Memphis, Lt. Toney Armstrong and his team respond to Memphis's worst mass murder in more than 15 years.

When a young man is gunned down outside a Cincinnati nightclub, witnesses see another young man running from the scene.

In Tucson, Detectives Jennifer Whitfield and Mike Carroll are called to investigate the robbery/homicide of 27-year-old cab driver.

In Miami, Sgt. Louis Melancon and Det. Carlos Castellanos investigate the murder of two men savagely gunned down in the middle of a residential street.

In Memphis, Sgt. Bart Ragland must find out who shot and robbed a family man.

In Minneapolis, just days before Christmas, Sgt. Rick Zimmerman and Sgt. Tammy Diedrich are called to the murder of a young woman.

In Cincinnati, Detectives Jenny Luke and Terry McGuffey investigate the murder of a 56-year-old man brutally beaten to death in the stairwell of his apartment building.