Lydia is suspended from duty and bonds with an injured witness. Chickie is haunted by a high-speed chase. John tries to clean up a neighborhood.

John gets an unexpected request from his ex-wife just as he, Ben and Chickie are sent out as part of a maximum deployment to capture the “Canyon Rapist,” a perp who has been impersonating a cop. Lydia gets re-partnered with Russell for a double-homicide case. And Sal gives his wife Susan a special gift to commemorate her promotion, but their night turns into a disaster when their daughter reveals Sal’s affair with TV news reporter Mia Sanchez.

Gangsters open fire in a crowded club and kill two bangers, one of whom has a connection to an officer. Meanwhile, tensions rise between Sal and Gil on the gang task force. And Sammy confronts his wife, Tammi, after discovering that she has been out photographing gang members.

Lydia and Rene arrive in Compton, where a young USC student was murdered. Kenny and Andy canvass the neighborhood while Nate and Sammy investigate a house nearby where a party took place the night before. John and Ben head to Indian Wells for the funeral of a cop that proves to be very personal for John.

They also stop at a halfway house for cops to see how Dewey is doing. And Lydia decides to talk to her mother about something that has been festering between them for years.

Ben winds up in a patrol unit alone for the first time. Among the cases he has to handle on his own are a missing girl and a suspected stalking case. Lydia and Rene spend the day checking in on and helping out Brianna and her baby.

Over in Gangs, Gil Puente leads the task force to take down ex-banger Trinny Day, but Sal and Sammy have a hard time working with Puente. While patrolling with John, it is clear that Chickie has no command presence, but she is determined to work harder and become a good cop again.

John and Ben are the first responders to a gruesome triple homicide in Hancock Park, where a mother is bludgeoned to death and her young daughters are found bound, gagged, raped and dead in their bedrooms.

In investigating the case, Lydia and Rene realize they have two very different styles of doing detective work. Sammy continues to have problems with his wife, who seems unable to complete even the simplest of tasks. And Ben confronts John about his increasing reliance on pain pills.

The second season opens with the search for a senior citizen kidnapped by a drug addict. Meanwhile, the investigation of a freeway shooting threatens an ongoing undercover operation, and Chickie’s new partner shoots at a teen and sets off a riot.