After two paramedics are murdered, the LAPD and the FBI investigate a case that could be the precursor to a terrorist attack.

The squad digs for clues in the slaying of an aspiring actress. All the while, Brenda gears up to interview for the job of chief of police, though she has mixed feelings about taking the post. Mary McDonnell reprises her role as Capt. Sharon Raydor

Brenda investigates the shooting deaths of three soldiers who had just returned from Afghanistan. With national-security issues surrounding the case, Brenda finds herself in an investigative tug-of-war with a military officer (Gary Cole).

A bank robbery leaves a security guard dead and a lot of unanswered questions; Pope gets some news about his chances at becoming the city's police chief.

After a parole board member is murdered, Pope announces a plan to boost the police department's image.

Detective Ramsky wants the squad to investigate a series of murders that indicate a Mexican drug cartel may have moved into the city.

Provenza discovers a dead body in the condo of a flight attendant that he picked up while extraditing a prisoner; Brenda reveals her career intentions to Pope.

As they probe a dubious suicide, Brenda and her squad are swept up in a fiery custody battle between a dying man and his drug-addled ex-wife. Meanwhile, Pope sets his sights on scoring the police-chief post.

Capt. Raydor (Mary McDonnell) arrives to help Brenda investigate the vanishing of a nanny who has connections to the mayor. But the case takes uneasy turns when a stun-gun-wielding rapist emerges as a suspect, and Raydor may have hidden motives for shadow