An Army investigating officer will now decide whether Pfc. Lynndie R. England should face a full-blown military trial on as many as 20 charges of abusing detainees and sexual misconduct, after hearing several days of testimony here about the soldier's alleged crimes at the Abu Ghraib prison in Iraq.

Army prosecutors at the base here Tuesday added a blanket charge of maltreatment and cruelty against the 21-year-old military police administrative clerk, who was captured last fall in several digital photographs apparently humiliating and abusing naked detainees. Col. Denise J. Arn, who presided over England's pretrial hearing, said she will consider all the charges over the next week and will then make a recommendation to a commanding officer.

A three-star general here then will decide whether England will face a court-martial that could send her to prison for nearly 40 years if she is convicted. England's attorneys said Tuesday afternoon that they believe England will certainly appear in a court-martial but again said that she has become a scapegoat for what has turned into a sprawling abuse scandal involving dozens of soldiers.

The hearing -- delayed multiple times and spread out over seven days of testimony and argument -- centered on England's role in a series of abusive acts, such as her appearing in a photograph holding a leash around a naked detainee's neck and her pointing at naked detainees as they were forced to masturbate. Witnesses testified that the abuse went unreported and that England appeared to enjoy the activities.

"She was having fun," said Capt. Crystal Jennings, one of three prosecutors on the case, emphasizing that England was an administrative clerk who had no official business on Tier 1A of the prison, where the most serious abuse occurred. "There's no indication she was there for a military purpose. . . . There were no orders. There's no evidence that Pfc. England was given any order to do these things."

But defense attorneys also tried to expose recent revelations that England and six other military police soldiers might have been acting in concert with military intelligence personnel to humiliate detainees as part of a sanctioned interrogation strategy. Two official Pentagon reports issued last week blamed widespread leadership failures in Iraq and the actions of nearly 50 soldiers linked to the abuse.

"Obviously, Pfc. England was not acting alone," said Richard A. Hernandez, her lead civilian defense attorney.

Jennings countered that the photographs of England speak for themselves. In statements to criminal investigators, England admitted taking part in the acts.

England also appears in a number of sexually explicit photographs -- some of which show her having sex with another soldier -- offenses that alone could result in significant prison time. It is unclear when England would face trial, though a decision could be made within weeks or months.