When an oil rig worker is found dead on shore, the investigation leads TJ and Winters to a drilling platform off the California coast.

The murder of a Watershed Management employee uncovers a cold case, and prompts the serial killer at its heart to come out of retirement.

The murder of golfer Kristin Halstead sends Detectives Winters and Jaruszalski to the Mens' professional circuit for leads, only to find them in Chip Jarrow. Trouble comes in the form of an incident between Jarrow and his wife Monica. Which leaves DDAs Dekker and Stanton to filter the chaos into a coherent case they can win.

Don Alvin's quiet life is destroyed when an intruder ambushes he and his family in their home, killing his wife and son. After searching for clues, the detectives discover similar cases that lead them to one powerful common thread. Meanwhile, DDA's Dekker and Rubirosa have to tread carefully in order to get a guilty verdict after Morales' puts their case in jeopardy.

When pre-med freshman Beth Garrett is found strangled to death, a mysterious text leads the detectives to a potential suspect. After some investigating at her sorority, the detectives learn that there is more to this mild mannered bookworm than initially meets the eye. Meanwhile, DDA's Dekker and Rubirosa are forced to change their strategy when game-changing evidence is discovered at the last minute.

When a crazed gunman open fires during a rally with State Senator Celeste Kelman, seven innocent people are killed including the Senator. With the help of modern technology, the detectives identify a solid lead and possible motive for the shooting. At the DDA's office, tensions are running high when Dekker and Rubirosa disagree on how to handle the case. Meanwhile, TJ gets himself into a sticky situation as he continues his quest to find his dead partner's killer.

When a destructive wildfire suddenly rips through the hills of Malibu, arson is immediately suspected. Once the blaze is contained, the detectives soon realize that a second fire was intended to cover up a gruesome crime. Meanwhile, DDA’s Dekker and Rubirosa stumble upon some information crucial to the case.

Following a heated argument with his cousin, casino worker George Patrick is found brutally murdered in his hotel bathtub. However, after talking with the victim's girlfriend, they discover that more than one crime has been committed. Meanwhile, DDA's Dekker and Rubirosa reluctantly strike a deal with those involved in order to convict the real mastermind.

Detectives Winters and Jaruszalski investigate a botched kidnapping, which becomes complicated when they discover another crime. Unfortunately, this dilemma leaves Dekker with a ticking clock as ICE threatens to extradite witnesses who are key to his case.

When Kim Ho Lee is found dead by a neighbor, the detectives suspect her live-in boyfriend of murder until they stumble upon his dead body. As Winters and Jazuszalski begin digging into Joyner’s past, they learn that he was hired to collect voter signatures in order to put a controversial proposition back on the ballot. However, when surprising details are uncovered, DDA’s Morales and Price find their case in jeopardy and justice hanging in the balance.