Heckler & Koch MP5A3 (from German: Maschinenpistole 5, "machine pistol model 5") is a 9mm submachine gun of German design, developed in the 1960s by a team of engineers from the German small arms manufacturer Heckler & Koch GmbH (H&K) of Oberndorf am Neckar. The MP5A3 is a variant of the MP5 with a retractable buttstock, "SEF" trigger.
The MP5A3 was seen in Olympus Has Fallen.
The weapon was used by Korean terrorist group Koreans for United Freedom (KUF) during their siege of the White House. Secret Service agent Mike Banning acquired a MP5A3 gun with a scope from one of the terrorists he killed in the Oval Office. Banning used it to take out the last terrorist in the roof access of the White House by shooting at his left foot and killed him with it when he was falling down. Kang Yeonsak, the head of the KUF and the mastermind of the takeover, planned to executed Secretary of Defense Ruth McMillan at the front door in front of the media, but Banning, who anticipated that Kang would try that movie, used the scoped MP5A3 to kill Kang's henchman Cho and another henchman with it from the stairway near the lobby.