A 73-year-old doctor who worked part-time as a physician at Rikers Island was arrested in his Harlem office this morning for his participation in an oxycodone drug ring that spanned five years and released millions of pills into the city. Authorities say Dr. Robert Gibbs wrote prescriptions for people who he had never met; the names and personal information of those "patients" were given to him by his 44-year-old accomplice Ronald Vaughn, who employed middlemen to fill the prescriptions in pharmacies across town. In their raid of Dr. Gibbs's office NYPD officers and DEA agents found $45,000 in cash, along with medical and financial records to be used as evidence.

In addition to his private practice, Dr. Gibbs treated inmates part-time at the clinic at the Vernon C. Bain center, part of the Rikers Island jail complex. A source close to the investigation says that Gibbs may have met Vaughn at the jail. Vaughn has three previous felony convictions, and served six months in jail for criminal possession of a controlled substance. "We don't believe that any of Gibbs's criminal activity happened at Rikers," the source notes. A spokesman for the Department of Corrections declined to comment.

Police say they became aware of Gibbs's and Vaughn's scheme during a rash of illegal prescription drug transactions at an Upper East Side pharmacy in July and August of 2011. Authorities assert that between January 2008 and August 2012, Gibbs wrote nearly 7,300 prescriptions for controlled substances—typically for 180 pills at a 30mg strength—and 88% were for oxycodone.

More than half of the controlled substance prescriptions Gibbs wrote went to a mere 9 percent of his patient population, prosecutors allege. He's charged with conspiracy, 42 counts of criminal sale of a prescription of a controlled substance, and several counts of criminal facilitation, and he voluntarily surrendered his DEA license to prescribe narcotics. Vaughn is charged with conspiracy, attempted criminal sale of a prescription for a controlled substance, and fraud.

A recent Pew study [PDF] showed that in 2009, 15,000 Americans died of overdoses related to opioid-based prescription drugs, more than heroin and cocaine combined.

“Dr. Gibbs betrayed his profession and Ronald Vaughan built an organization with one goal: to rake in hundreds of thousands of dollars selling addictive drugs," New York City's special narcotics prosecutor, Bridget Brennan said in a release. "Both men lined their pockets and caused untold misery by flooding our streets with deadly painkillers."

Robert Doar, the city's human resources administration commissioner, added, “Doctors like Dr. Gibbs represent two serious kinds of Medicaid fraud: inappropriate use of a professional license and taking advantage of Medicaid recipients, sometimes with deadly consequences. HRA will continue to work with our partners in law enforcement to find and weed out these schemes that hurt people and waste taxpayers' money."

A spokesperson for the Mayor's Office, Samantha Levine, said in an email, "A doctor was arrested today for allegedly writing illegal oxycodone prescriptions to private patients. It is unconscionable that a doctor would abuse his profession for personal gain in a way that harms the public."