FORT MEADE, Md. — Jurors began deliberations yesterday at the court-martial of the only American military officer charged in the Abu Ghraib detainee abuse scandal, after the defense accused a witness of lying on the stand to deflect blame away from himself.

Lieutenant Colonel Steven Jordan, 51, of the Army never appeared in the inflammatory photos of American soldiers with naked and abused detainees at Abu Ghraib, but he was the highest-ranking officer at the Iraq prison at the time and was accused of fostering the abuse.

If convicted on all four counts against him, he could be sentenced to 8 1/2 years in prison.

During closing arguments, Colonel Jordan’s lawyer took aim at one of the government’s top witnesses, saying that Major Donald Reese falsely testified that Colonel Jordan condoned prisoner nudity as an interrogation technique. Major Reese commanded the 372 Military Police Company in Iraq. “Major Reese is not telling the truth,” a defense attorney, Major Kris Poppe, said, citing contradictory testimony by others. “To deflect blame is a time-honored tradition, and that’s what he did.”

Major Reese’s testimony Tuesday was among the government’s strongest evidence supporting the charge that Colonel Jordan, of Fredericksburg, Va., willfully failed to train, supervise, and ensure that soldiers under his control followed interrogation rules. Earlier yesterday, a prosecutor said in the government’s closing that Colonel Jordan is not being court-martialed for what he did during his brief assignment as director of the Abu Ghraib interrogation center — but for what he didn’t do.

“It’s about what he divorced himself from doing,” Lieutenant Colonel John Tracy told the panel of nine colonels and one brigadier general. “He didn’t train. He didn’t supervise.”

Colonel Tracy reminded the panel repeatedly that Colonel Jordan was the senior officer at Abu Ghraib in September and October 2003, when witnesses said they saw detainees naked and handcuffed in their cells. Colonel Tracy also said Colonel Jordan was the senior officer inside a prison cellblock on November 24, 2003, during at least part of an episode that ended with a dog being brought in to intimidate a detainee during questioning.

The defense contended that Colonel Jordan had no obligation “to train, supervise, and ensure compliance by soldiers under his control” in following interrogation rules requiring humane treatment of prisoners.

Colonel Jordan’s attorneys extracted testimony from witness after witness that his two-month stint as director of the prison’s interrogation center placed him outside the chain of command of both the military intelligence soldiers who interrogated detainees and the military police who guarded them.

The most serious charge Colonel Jordan faces is disobeying an order not to discuss an Abu Ghraib investigation with others, an offense punishable by up to five years in prison.

Colonel Jordan also is charged with failing to obey a regulation by ordering dogs to be used for interrogations without higher approval, punishable by up to two years; cruelty and maltreatment for allegedly subjecting detainees to forced nudity and intimidation by dogs, punishable by up to one year, and dereliction of a duty to properly train and supervise soldiers in interrogation rules, punishable by up to six months.

Overall, 11 enlisted soldiers have been convicted in the case.