A lot of federal government agencies have what is called an Employee Assistance Program (EAP), which offers support to sworn and civilian employees for all manner of personal crises. They usually offer referral services for therapy, counseling, etc. For instance:
DEA
http://www.justice.gov/dea/programs/eap/index_about.html I can only assume that law enforcement acts similarly on a more granular (ie state or local) level.
As far as veterans go, I have no idea, but I would maybe start looking around on the Department of Veteran Affairs website. They have a special section on post-traumatic stress disorder:
http://www.ptsd.va.gov/ They actually have a guide concerning returning from war:
http://www.ptsd.va.gov/public/reintegration/returning-war-zone-guide-sm.asp
