After seven years of delays and legal wrangling, four former guards with the security firm once known as Blackwater go on trial in Washington Wednesday, charged with killing Iraqi civilians in 2007.
The trial begins with jury selection.
The four defendants allegedly shot Iraqi civilians trying to flee from a traffic circle in downtown Baghdad after a car bombing that apparently targeted a U.S. State Department official.
The defense plans to argue that the guards acted in self-defense because they say the Blackwater team was under fire from insurgents.
U.S. government prosecutors will likely contend that the use of deadly force was unnecessary. They plan to call Iraqi civilians and another Blackwater guard who already pleaded guilty as witnesses.
One of the guards is charged with first-degree murder and faces life in prison if convicted. The other three are charged with manslaughter and would face at least 30 years behind bars.
A U.S. District judge threw out the case against the guards in 2010, but an appeals court later reinstated the charges.