RALEIGH, N.C. — In the weeks after the Abu Ghraib prison scandal stunned Iraq, a story emerged from Afghanistan about a CIA contractor accused of beating a detainee so severely that he later died.

More than three years later, after several soldiers working at Abu Ghraib have been sentenced to military prison, the contractor, David Passaro, will finally stand trial when jury selection begins today — in a civilian court in his home state of North Carolina.

The former Special Forces medic is the first, and so far only, civilian charged with mistreating a detainee during the American wars in Iraq and Afghanistan.

To bring charges against Mr. Passaro, who isn’t subject to military justice, prosecutors turned to the USA Patriot Act, arguing the law passed after the September 11, 2001, terrorist attacks allows the government to charge American nationals with crimes committed on land or facilities designated for use by the American government.

When U.S. District Judge Terrence Boyle agreed with them last year, prosecutors essentially received a license to enforce the nation’s criminal laws in “any foxhole a soldier builds,” a Duke University law professor, Scott Silliman, said.

“What we’re seeing is Congress moving to ensure there is criminal accountability for civilians accompanying the forces,” Mr. Silliman, who runs Duke’s Center on Law, Ethics, and National Security, said.

Mr. Silliman said the law represents a dramatic expansion of the reach of federal prosecutors, whose jurisdiction most experts believed was limited to places like embassies and consulates, and not locations like the remote American base in Afghanistan where the detainee, Abdul Wali, turned himself in to American forces.

“What the Patriot Act said was that part of Afghanistan is now part of our … jurisdiction,” Mr. Silliman said. “The charge of assault is as if it had occurred in Raleigh. All you have to show [is] it’s an assault.”

Neither prosecutors nor defense lawyers were willing to talk about the case, which is expected to include a significant amount of evidence considered classified by the government. Before the trial, a secure area was built inside the courthouse so lawyers could be safe from electronic eavesdropping while they review classified material.

The government has said its case includes three paratroopers from the Army’s 82nd Airborne Division, who will testify they saw Mr. Passaro beat Wali with his hands, his feet, and a flashlight in June 2003, during two days of questioning about rocket attacks on a remote firebase housing American and Afghan troops.

Wali later died in his cell, although Mr. Passaro isn’t charged with his death. Instead, he faces two counts of assault with a dangerous weapon and two counts of assault resulting in serious injury. If convicted, he will face up to 40 years in prison.

Mr. Passaro, 39, of Lillington, N.C., has maintained his innocence, calling the charges a “knee-jerk reaction” by the Bush administration to the Abu Ghraib scandal. His attorneys have said they want to call a former director of central intelligence, George Tenet, and a former White House counsel, Attorney General Alberto Gonzales, as part of a “public authority defense” — namely, that Mr. Passaro was following orders.

Such a defense could be a challenge. Judge Boyle has limited the defense’s access to several classified documents and e-mails, including a memo that Mr. Passaro believes the Justice Department gave the CIA on what kind of interrogation techniques American law allowed. But until Mr. Passaro shows who approved his actions in Wali’s interrogation, Judge Boyle has ruled such documents — if they even exist — will remain off-limits.

And suggesting an atmosphere of vague rules, as is sometimes done in military cases, would be “a very hard sell” with a civilian jury, the president of the National Institute of Military Justice, Eugene Fidell, said.

It’s not clear if Mr. Tenet, Mr. Gonzales, or any other Bush administration official will actually testify, since the prosecution and defense witness lists are among the many court documents under seal. The trial comes amid a renewed focus on the actions of Americans in the Middle East. Officials are investigating allegations a group of Marines deliberately shot 24 Iraqi civilians in Haditha last November.