source: In flashback, it is shown that he was part of Operation Cerberus with Castle and a former US Navy Special Amphibious Reconnaissance Corpsman.
target: He was part of Operation Cerberus.  This was along with Castle and a former US Navy Special Amphibious Reconnaissance Corpsman. It is shown in flashback.
references: He was part of Operation Cerberus.  This was along with Castle and a former US Navy Special Amphibious Reconnaissance Corpsman. It is shown in flashback.