WASHINGTON (AP) — The government said Wednesday it might seek new criminal charges against one of four former Blackwater security guards in the shootings of dozens of Iraqi citizens at a traffic circle in Baghdad in 2007.

A federal judge dismissed an indictment against defendant Nicholas Slatten after a federal appeals court said the statute of limitations had lapsed before the government filed the charges against Slatten last October.

Slatten had been charged with manslaughter, attempted manslaughter and using a firearm in a crime of violence.

The government might seek to bring new charges against Slatten that could become part of the scheduled June 11 trial of the other three Blackwater guards in the case, Anthony Asuncion, the lead prosecutor, said at a hearing before U.S. District Judge Royce Lamberth.

A range of federal crimes do not carry a statute of limitations, including murder. The statute of limitations restricts the time in which legal proceedings may be brought.

Asuncion works for the U.S. Attorney's office in Washington, D.C., which is handling the prosecution of the Blackwater guards.

The shootings in Nisoor Square on Sept. 16, 2007 killed 14 Iraqi citizens and wounded 18 others.

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

The government has portrayed Slatten as a central figure in the violence that day. In a court filing a month ago, federal prosecutors said evidence at the trial will show that Slatten fired the first shots at Nisoor Square, initiating the entire incident by firing his sniper rifle without justification at a driver who was stopped just south of the circle.