Updated

Federal prosecutors have obtained a new indictment against a former Blackwater security guard accused of taking part in a shooting of Iraqi civilians at a Baghdad traffic circle.

A grand jury indictment issued Thursday charges Nicholas Slatten with first-degree murder. The indictment comes just weeks after a judge dismissed all charges against Slatten because of statute-of-limitation concerns.

Slatten and three other guards are scheduled to stand trial in Washington's federal court next month on charges arising from the September 2007 shootings. The contractors are accused in the deaths of 14 Iraqis and the injuries of more than a dozen others, shootings that inflamed anti-American sentiment in Iraq.

Prosecutors have portrayed Slatten as a central figure in the shootings, arguing that he fired the first shots at Nisoor Square without justification at a driver who was stopped at the traffic circle.  In a statement Friday, the U.S. Attorney's office called that killing "intentional and unprovoked."

Defense attorneys for the Blackwater guards have said their clients were fired upon first, and returned fire in an act of self-defense.

Slatten's lawyer, Thomas Connolly, declined to comment Friday.