Assassination / Targeted Violence Against Public Officials and Public
   Figures Assassination in the United States: An Operational Study of
   Recent Assassins, Attackers, and Near Lethal Approaches (5.7M)
   Protective Intelligence & Threat Assessment Investigations "A Guide for
   State and Local Law Enforcement Officials" (194K) Threat Assessment: An
   Approach to Prevent Targeted Violence (243K)
   [1]http://www.ustreas.gov/usss/ntac.[2]shtml

References

   1. http://www.ustreas.gov/usss/ntac.shtml
   2. http://www.ustreas.gov/usss/ntac.shtml