
Blackwater USA contractors secure the site of a roadside explosion in central Baghdad in 2005. The U.S. Embassy said a Blackwater convoy accused of killing eight civilians during a shootout in the capital Sunday had come under fire, and some local Iraqi television stations reported an exchange of gunfire at the scene. (Ahmad Al-Rubaye / AFP / Getty Images)

Then-U.S. Ambassador Zalmay Khalilzad is shown in 2005 surrounded by Blackwater bodyguards. (Patrick Baz / AFP / Getty Images)

Blackwater contractors, shown in 2005, have an arsenal of helicopters, turreted armored vehicles and automatic weapons at their service. (Marwan Naamani / AFP / Getty Images)