The appeal filed in October with the U.S. Court of Appeals for the Armed Forces raises the same legal issues that were before the Army appeals court.
Behenna's civilian attorneys say prosecutors and the judge in the court-martial made mistakes that deprived Behenna of a fair trial.
They contend prosecutors improperly failed to disclose that one of their own witnesses — a crime scene expert who was never called to testify — would have supported Behenna's story that Mansur was standing and reaching for Behenna's gun when the soldier shot him.
And the judge in the original court-martial obscured distinct legal points of self-defense when he gave the jury instructions on how to consider a verdict, the appeal argues.
The U.S. Army declined last fall to file a response challenging Behenna's latest appeal, relying on its arguments to the Army criminal appeals court that no favorable evidence was withheld from the defense and that the “overwhelming evidence” in the case showed that Behenna “gave up his right to self-defense” because he was armed and pointing a gun at Mansur, who was naked and unarmed when killed.