"I thought it was too good to be true, I thought I was being set up in some way," said O'Brien, 23. "It was too easy."
As Ruth's trial opened in Norristown, prosecutors described the basement office of the doctor's Cherry Lane home as a lucrative pill mill that turned his patients into addicts. Some lost their jobs, others went on to use heroin or have other troubles.
Ruth, 78, faces nearly 50 counts, including charges of prescribing to drug dependent people, prescription fraud, insurance fraud, identity theft, dealing in proceeds of unlawful activities, and corrupt organizations. Also on trial is his 46-year-old son, Michael, who was his lone office worker.
The investigation started in 2010, after Telford Borough police and other authorities began noticing a thread in various cases in which suspects used or sold prescription drugs. Many were Ruth's patients.
Investigators determined that Ruth prescribed 242,598 Oxycodone tablets between May 2010 and April 2011, most often to adults between 20 and 30.
"He cultivated users so they would come back to his office, week after week, to feed their addiction," Assistant District Attorney Rebecca Strubel told jurors.
Ruth's lawyer, John L. Walfish, described his client as a "local boy" who grew up in the area and returned to practice medicine so he could give back to his community.
Ruth wasn't hooking people on drugs, Walfish said. He was trying to quickly and effectively relieve his patients' pain, since many lived paycheck to paycheck and could not afford to miss work.
As testimony began, prosecutors called former patients who said they had become addicted to the drugs Ruth prescribed. First Assistant District Attorney Kevin Steele showed prescriptions Ruth had written, some of which were for 170 pills at a time, and which were rewritten weeks apart in the same large quantities.
A mother and a wife of two ex-patients said they asked Ruth to stop prescribing the Oxycodone because their loved ones had become hooked. Yet the drugs continued, they said.
The testimony Tuesday did not touch on a possible motive. Court filings suggested that Ruth said that his wife had lost $600,000 - or half their investments - in a Nigerian scam.
The trial is expected to last most of the week.