Updated

Relatives of an Oklahoma soldier convicted of killing an unarmed Iraqi prison detainee say they're surprised a military appeals court upheld his conviction.

The Oklahoman reports Saturday (http://bit.ly/Ne0mcv) that Scott and Vicki Behenna said they will pursue all possible legal avenues to bring their son, Michael, home.

A military appeals court on Thursday narrowly rejected Michael Behenna's request to overturn his 2009 conviction for unpremeditated murder in a combat zone.

Prosecutors say Behenna shot the detainee execution-style after interrogating him at gunpoint about a 2008 roadside bombing that killed two men under Behenna's command.

Behenna's father says he is confident his son was acting in self-defense.

Behenna, who is from Edmond, Okla., is serving a 15-year prison sentence at a military prison in Fort Leavenworth, Kan.