A onetime pharmacist in Burnsville pleaded guilty Wednesday to stealing tens of thousands of doses of oxycodone and other powerful painkillers that she took to feed her addiction for two years.

Anissa J. Shores, 37, admitted in federal court in St. Paul to obtaining controlled substances by fraud while working at the Fairview Pharmacy inside the Ridgeview medical office building next to Fairview Ridges Hospital.

According to the charges and court documents, Shores began stealing from the pharmacy in 2011, taking hydrocodone, oxycodone, carisoprodol and diazepam, all controlled substances, as well as tramadol, a noncontrolled substance.

The total number of doses reached 67,000, authorities alleged, with a street value of more than $500,000.

Shores, of Burnsville, "abused her position as a trusted member of the medical community by diverting significant quantities of opioid-based prescription drugs," said Dan Moren, assistant special agent in charge of the Drug Enforcement Administration.

U.S. Attorney Andy Luger characterized prescription drug abuse as "both a law enforcement and public health challenge. Pharmaceutical drugs taken without a prescription or a doctor's supervision can be just as dangerous as using illegal drugs like heroin."

Shores' attorney, Ryan Garry, said her employer discovered the thefts in the spring of 2013 and fired her. After she was caught, he said, she enrolled in a treatment program and completed it.

Shores remains free on a bond ahead of sentencing. The plea agreement calls for a federal-guideline sentence of zero to six months in prison.

"Addiction with these types of drugs is very scary, and I don't think I have ever had a client accept as much responsibility for her actions as Anissa," Garry said. "Unlike most people, when she finally knew she had a problem, she went to the ends of the earth to get herself better, which she did. I'm confident the court will recognize that."

According to court documents, Shores was responsible for maintaining inventory records of controlled substances at the pharmacy. She falsified those logs to make it appear that the pharmacy received smaller quantities than it actually received, then kept the remainder for herself.

Fairview officials Wednesday night declined to elaborate on how Shores' thefts were detected and whether anything has been done to prevent similar incidents in the future.

Paul Walsh • 612-673-4482