I'll try and play, Q…
Who is the Diplomatic Security Service (DSS)?
https://en.wikipedia.org/wiki/Diplomatic_Security_Service
State Department: Diplomatic Security's Recent Growth Warrants Strategic Review (2009)
https://www.gao.gov/products/GAO-10-156
Diplomatic Security: Key Oversight Issues (2017)
https://www.gao.gov/products/GAO-17-681SP