That photo resulted in a charge of conspiracy against his client, said Harvey J. Volzer, who said Ambuhl worked the nightshift at the prison with five other guards who are facing criminal charges.
All are members of the 372nd Military Police Company in Cresaptown.
Few details have surfaced about Ambuhl, who is not mentioned by name in the scathing 53-page Army report by Maj. Gen. Antonio M. Taguba describing prisoner treatment at Abu Ghraib that has provoked shock and outrage around the world.
Volzer said he received a report yesterday of military investigators' findings after Ambuhl's Article 32 hearing, the military equivalent of a grand jury proceeding.
Ambuhl was referred for a general court-martial on the conspiracy charge and a count of dereliction of duty, but two of the four original charges brought against her were dropped, he said.
Military officials in Iraq could not been be reached for comment.
"Frankly, with the remaining charges, I'm not worried at all," Volzer said. "We couldn't have expected a better result from an Article 32."
It is up to Lt. Gen. Ricardo Sanchez, the commander of U.S. forces in Iraq, to make the final determination of whether she should face a court-martial.
Another of her fellow nightshift guards, Spc. Jeremy C. Sivits of Hyndman, Pa., will be the first to face a military court in Baghdad on May 19.
Ambuhl, one of three female reservists facing charges, has attracted the least publicity, partly because she has not appeared to date in any of the widely publicized photographs. Her parents and family members -- unlike some of the other reservists' relatives -- have steadfastly refused to comment to the media.
Ambuhl, 29, grew up in a Northern Virginia suburb, a different setting from some of the other reservists charged in the scandal who hail from small, hardscrabble towns in West Virginia and Pennsylvania.
She was raised in Herndon, in a leafy neighborhood known as Fox Mill Estates.
Ambuhl attended Oakton High School in nearby Vienna, a campus of low buildings flanked by acres of athletic fields and surrounded by trees. She played softball her freshman and sophomore years and belonged to a marketing club in her junior year, according to her senior yearbook.
After graduation in 1992, she attended Coastal Carolina University, in Conway, S.C.
There, she majored in biology and participated in two major annual trips -- to the Galapagos Islands and to Kenya -- where students studied plants and animals, according to a professor who organized the trips.
She graduated in 1998, school records showed.
After college, Ambuhl worked as a lab technician in the Herndon clinical testing office of Laboratory Corp. of America Holdings, Volzer said. She joined the Army as a reservist shortly after the terrorist attacks of Sept. 11, 2001, he said.
Ambuhl's parents eventually moved from Herndon and now live on a cul-de-sac in Centreville. At their home yesterday afternoon, no one answered the door, though a car was parked in the driveway. Several phone calls to their residence were not returned.
A postcard-sized sticker of an American flag in the window next to their front door reads: "Freedom Isn't Free."
Sun staff researchers Paul McCardell and Sandy Levy contributed to this article.