DARPA is short for Defense Advanced Research Projects Agency.
Jarred refers to the guards as "Blackwater wannabes." This is a reference to the company that supplied mercenaries that were hired by the U.S. government to supply support services during the invasion of Iraq and afterwards. Having much of the same weapons and gear of the military, they became controversial when some of them exceeded the rules of engagement and, in at least one case, abused innocent Iraqi civilians.