Sinners and Saints (2010) on Netflix

Plot summary

Sean Riley heads the violent offenders warrant squad for the New Orleans police, and the job has worn him down since his young son died and his marriage ended. When his partner is killed during a warrant, his commander, Captain Trahan, moves him onto a homicide case: someone has been burning the city's gang leaders, and one victim was the younger brother of the gangster Weddo. The killings have set off a gang war. Riley's new partner is Detective Will Ganz, a family man who is out of his depth on the case. The two interrupt mercenaries burning another body, and a gunfight breaks out. Colin, an old army friend of Riley's, gets back in touch.