Penny Parker Green had spent nearly her entire professional life at the Arc of Prince George’s County, starting out as a low-level counselor while she was in college and working her way up to become a high-ranking administrator in charge of operating the nonprofit organization’s 52 group homes, authorities said. Along the way, she claimed to have earned multiple advanced degrees while performing well in her day-to-day tasks, authorities said.

“People just thought the world of her,” said Mac Ramsey, executive director of the Arc, which serves people with intellectual and developmental disabilities.

In a conversation in February, though, Ramsey was tipped that Green might not have the education she claimed. As he probed further, he said, he found evidence that the problem went deeper.

Green, according to Ramsey and federal authorities, had been buying furniture and booking travel for herself, then leaving the Arc or its group home residents with the bills. She was arrested and charged in federal court last week with wire fraud.

“It was, quite frankly, shocking and unbelievable, because she was well liked by all of us,” Ramsey said. “We’re sitting here as an organization that works on behalf of people with disabilities and their families, and we let this go on in front of us.”

Before they turned the investigation over to police, auditors hired by the Arc of Prince George’s, a Largo-based group, found that Green had stolen between $136,598 and $166,137 from the organization and those in the homes it runs, according to an affidavit filed in federal court in Maryland. Using an Arc-provided credit card, funds from Arc bank accounts and petty cash, Green, 33, of Bowie, bought clothing, furniture and even a lavish trip for herself, then submitted forged paperwork suggesting the items were for group home residents, according to the affidavit.

In July, for example, Green used an Arc credit card to buy $266.85 in merchandise from Ashley Stewart in Oxon Hill, then claimed that the items were for two group home residents so their accounts would be debited, authorities said in the affidavit. In September, Green used an Arc credit card to buy $1,500.98 worth of furniture from Marlo Furniture in Forestville, again submitting false paperwork and debiting a resident’s account, the affidavit said.

In August 2009, according to the affidavit, Green booked a $1,264.94 vacation through Expedia, altering copies of the receipt to make it appear that the travel reservation was for two group home residents to go to Miami. According to the affidavit, Miami was a layover for Green and her husband on their way to Aruba, where they had booked a sunset sail and island tour.

Ramsey said that as the associate executive director for residential services, Green had “wide discretionary authority” to make purchases on behalf of the Arc and those in its group homes, and it would not be unusual for her to purchase clothing or vacations for residents. Six group home residents are listed as victims in the affidavit.

Ramsey said that residents whose accounts were charged falsely have been reimbursed and that the Arc sent a letter to family members letting them know what had happened.

Ramsey said he was first tipped something was amiss with Green — a 13-year employee — in a conversation with someone from George Mason University, where Green said she earned a doctorate in clinical psychology. Ramsey said he brought up Green — highlighting the good work she had done for the Arc — and the person claimed to have never heard of her.

Ramsey said he soon learned that Green had neither a doctorate from George Mason nor a master’s degree from Bowie State University — which she also claimed to have earned while working at the Arc. The advanced education was not required for Green’s job and earned her no extra pay. Ramsey said he put her on administrative leave and asked her to provide proof of the degrees. A few days later, he said, she resigned.

Federal authorities arrested Green last Wednesday, but she has since been released to her husband, court records show. She was ordered to turn in her passport, and her travel has been restricted to the Washington area.

Richard A. Finci, Green’s attorney, said he was reviewing documentation in the case and could not comment on the allegations against his client.