U.S. Army Pfc. Lynndie England -- convicted Monday of prisoner mistreatment for posing for notorious Abu Ghraib prisoner abuse photos -- apologized Tuesday and blamed her boyfriend.

During her unsworn statement to the jurors who will determine her punishment, England blamed Pvt. Charles Graner Jr. for what she did.

U.S. Army Pfc. Lynndie R. England arrives at the courthouse Sept. 27, 2005, in Fort Hood, Texas. (AP Photo/Tony Gutierrez)

"I was used by Pvt. Graner," she said. "I didn't realize it at the time."

England, the most recognizable of the nine enlisted soldiers charged in the scandal after photos of the abuse became public, was convicted of six of the seven counts she faced. She faces a maximum of nine years in prison.

Her defence has maintained throughout the trial that she took part in the prisoner abuse to please Graner, who prosecutors have labeled the ringleader of the abuse by a group of U.S. troops.

Earlier Tuesday, defense witness Stjepan Mestrovic, a sociology professor at Texas A&M University who has interviewed England, said officers in charge failed to control the guards, creating stressful conditions that disoriented her and led her to take part in the mistreatment.

"She was caught up in this chaotic situation like everyone else," said Mestrovic, who also testified that officers at Abu Ghraib "knew or should have known what was going on."

That testimony was supported by Graner, who's now serving a 10-year sentence. He said he once severely beat a detainee while military intelligence personnel watched.

England, a 22-year-old reservist and former chicken factory worker from rural West Virginia, was photographed at Abu Ghraib holding a naked prisoner on a leash. In other images, she posed with a pyramid of naked detainees and pointed at the genitals of a prisoner while a cigarette hung from the corner of her mouth. She is pictured in several images giving a thumbs-up to the camera while posed with prisoners.

Her court-martial was the last of the nine. Two Abu Ghraib guards were convicted earlier, and six others struck plea bargains. No officers have gone to trial, though several have received administrative punishment.

Graner, 37, testified that he, England and others who worked the overnight shift in a high-security section of Abu Ghraib had scant supervision.

"It seems like the junior soldiers were on their own," Graner said. "We had little leadership."

Graner said he told officers about prisoner abuse, which he claimed was done on orders from military intelligence personnel. And at times, he said, the intelligence personnel were actually present for the abuse.

"I nearly beat an MI detainee to death with MI there," he said before Col. James Pohl, the judge, interrupted his testimony.

Also Tuesday, a New York psychologist said England came from an emotionally abusive family, was prone to depression and suffered from post-traumatic stress disorder even before she was sent to Iraq.

Xavier Amador said England also had a deviant sexual relationship with Graner that affected her ability to know her actions were wrong.

"It changes your view of what's OK and what's not OK," he said. "You don't recognize indecent acts as readily as you would have."

During her trial England was depicted as having an overly compliant personality and wanting to please Graner, who is the father of her 11-month-old son.