Detective Lyons said he is a member of NSID, which is short for Narcotics & Special Investigations Division , which is a part of the Washington D.C. Metropolitan Police Department.
JSOC, as mentioned with respect to Ava, is short for Joint Special Operations Command, and it is a subdivision of Special Operations Command (SOCOM). It is primarily responsible for direct action, or counter-terror operations.
NSC is short for the National Security Council, it is responsible for developing the country's National Security and Foreign Policy.
A court-martial is a judicial court for trying members of the armed services accused of offenses against military law.
Yazidis, are a group of people which are ethnically Kurds, and generally found in Northern Iraq. They practice a syncretic religion, that is a faith composed of elements from Zoroastrianism (an ancient Persian faith founded by the philosopher Zoaraster), Christianity and Islam.