S4·E2 The Devil You Know...

After Chief Strickland causes the death of an innocent old lady due to having inaccurate information on the whereabouts of a dangerous drug lord, Mannion decides to catch the guy himself. He uses the help of his best men, who put their jobs at steak and work parallel to Strickland's orders. Mannion's house is burnt down after he keeps stopping kids from selling drugs. When Mannion finally catches the guy, Mayor Douglas won't give his job back, so Jack is forced to reveal that he knows the phone wire was illegal, which ultimately forces Douglas to give him his job back. Meanwhile, Temple investigates two cops whom he thinks are abusing their authority and beating the people they arrest, while Debreno sleeps with Maria Rodriguez, which causes some conflict on his friendship with Temple.