LOUISVILLE, Ky. — A former U.S. Army soldier who raped a girl and killed her and three family members in Iraq challenged his convictions Monday, saying he was wrongly tried in a civilian court and should have faced a military trial.

In a 71-page appeal filed with the U.S. 6th Circuit Court of Appeals, attorneys for Steven Dale Green are seeking to have the law used to prosecute him — the Military Extraterritorial Jurisdiction Act — overturned.

The law, passed in 2000, allows the federal government to try former soldiers, their spouses and contractors in civilian courts for crimes that happened overseas.

“That’s the overarching issue,” said Green’s defense attorney, Darren Wolff of Louisville.

Green is also contesting whether the military validly discharged him before he was charged in civilian court.

A message left for the U.S. Attorney’s Office in Louisville, which prosecuted Green, was not immediately returned Monday. Prosecutors have until Jan. 5 to file a response.

A jury convicted Green, 24, a former 101st Airborne soldier, in June of raping and killing 14-year-old Abeer Qassim al-Janabi. He also was convicted of killing three of her family members in the March 2006 attack.

Green, of Midland, Texas, is serving a life prison sentence without parole. The other four soldiers charged in the plot faced military trials, known as a court martial.

Federal Public Defender Frank Heft wrote that Green faced severeer punishments in civilian court, which violated his rights to equal protection and due process.

Much like the strategy at trial, the appeal does not contest Green’s guilt in the crimes near Mahmoudiya, Iraq, about 20 miles south of Baghdad.

Wolff said the goal of the appeal, a first-of-its-kind challenge to the law, is to have the law thrown out and the indictment dismissed. That would mean the federal government would have to retry him under the Uniform Code of Military Justice.

To do that, the appeals court would have to declare the law unconstitutional and declare Green’s discharge invalid, meaning he would have still been active in the military and eligible for court martial.

“There’s no net to catch guys who have been discharged,” Wolff said.

Before trial, U.S. District Judge Thomas B. Russell of Paducah rejected arguments nearly identical to the ones being made in the appeal, saying the law passes constitutional muster and there’s no evidence the Army erred in discharging Green.

Green and four other soldiers based at Fort Campbell, Ky., were investigated after Abeer was raped and her body set afire.

Green had been honorably discharged with a personality disorder and returned to the U.S. by the time the Army charged him in June 2006.