NCIS Season 6 Episode 15

Marines private first class Emilio Salazar (18), recruited 4 months ago, from age 12 member of the Pecados Capitales (PCs) street gang, is fatally shot in Liberty Heights- by pistol, 6 hours later by machine gun, and strung-up by cuffs. Jethro contacts his NIS mentor Mike Franks, believing it's because of their 18 years old Cali drug cartel mission, which involved the late Rose, whose son marine private first class (also ex PC) Tomas Tamayo's blood was used to write Gibbs's service no. The fatal bullet traces to PC Victor 'Popeye' Carmado, who makes a false confession. So does their USMC platoon commander, staff sergeant Vincente Medina, also ex-PC. It ties to gun theft and someone else.