Prosecutors are seeking dismissal of charges against a former Blackwater Worldwide security contractor accused in a 2007 shooting of Iraqi civilians.

In a court filing Monday, the U.S. Attorney's office in Washington, D.C., asked a federal judge to dismiss the indictment against Donald Wayne Ball "with prejudice" — meaning that he could not be charged again in the case.

The Sept. 16, 2007, shooting occurred when security contractors guarding U.S. diplomats opened fire in Nisoor Square, a crowded Baghdad intersection, killing 17 Iraqi civilians. A federal appeals court in 2011 resurrected the case against the contractors after a judge had earlier dismissed it. Prosecutors are weighing whether to move forward with charges against four other contractors.

The U.S. Attorney's office said the government has exercised its prosecutorial discretion in ending the case against Ball based on its assessment of the admissible evidence against him.

Ball's lawyer, Steven McCool, disputed the government's characterization, saying prosecutors had no evidence that his client had broken the law.

"It is disingenuous to suggest that Donald Ball is anything other than an innocent man who was wrongly accused of a crime," McCool said Monday.