More than 50 medical professionals were charged by the Department of Justice on Wednesday with illegally distributing more than 32 million opioid pills, including one doctor who allegedly exchanged pills for sexual favors and a dentist who “unnecessarily” pulled patients’ teeth to justify prescribing the highly addictive drugs.

The charges are the result of a widespread investigation conducted by the Appalachian Regional Prescription Opioid Strike Force, created last year to target a region of the country that’s been particularly ravaged by the ongoing opioid epidemic, which has already claimed tens of thousands of American lives. Investigators and confidential informants infiltrated suspicious clinics, using cameras and tape recorders to capture the alleged crimes, The Washington Post reports.

“That is the equivalent of one opioid dose for every man, woman and child in the five states in the region that we’ve been targeting,” said Brian Benczowski, an assistant attorney general in charge of the Justice Department’s criminal division. “If these medical professionals behave like drug dealers, you can rest assured that the Justice Department is going to treat them like drug dealers.”

As a result of the investigation, 31 doctors were charged, alongside seven pharmacists, eight nurse practitioners, seven other licensed medical professionals, and seven others, the DOJ said in a press release. The charges include unlawful distribution or dispensing of controlled substances by a medical professional, health-care fraud, and conspiracy to obtain controlled substances by fraud.

A whopping 32 people face charges in Tennessee, including one doctor, the self-branded “Rock Doc,” who was accused of exchanging the highly addictive drugs for sexual favors. In just three years, the press release states, the Rock Doc allegedly prescribed “500,000 hydrocodone pills, 300,000 oxycodone pills, 1,500 fentanyl patches, and more than 600,000 benzodiazepine pills,” sometimes in exchange for sexual favors, and sometimes in “powerful and dangerous” combinations.

Similar charges were brought against a doctor in Alabama, who stands accused of recruiting prostitutes and other young women with whom he’d had sexual relationships to become his patients—and opening up his home for their illicit drug use. Another Alabama doctor allegedly doled out prescriptions to patients he knew to be addicts, collecting a “concierge fee” of $50 per visit or $600 a year. Yet another is accused of handing out “excessive” quantities of drugs to some patients that amounted to up to 15 pills a day.

In the Eastern District of Kentucky, a dentist stands accused of pulling patients’ teeth unnecessarily to justify prescribing opioids. A doctor was accused in the same district of prescribing opioids to his Facebook friends, who would come to his home to pick up their doses. That doctor also allegedly signed off on prescriptions for his office manager, who would deliver opioids to patients’ home in exchange for cash.

In Ohio, six people were charged, including a doctor who was believed at one time to be the highest prescriber of controlled substances in the state, and several others who allegedly ran a “pill mill” in Dayton that gave out 1.75 million pills between October 2015 and October 2017 alone.

This isn’t the first time federal prosecutors have gone after illegal narcotics schemes. Last summer, the Justice Department charged 162 people—including 76 doctors—with prescribing and distributing opioids and other dangerous drugs.

Federal officials say this is just the beginning. “Today’s takedown demonstrates the FBI’s unwavering commitment to working alongside our Strike Force partners, including the HHS-OIG and DEA, to fight the opioid epidemic and related criminal activity in the Appalachian region,” FBI Executive Assistant Director Hess said in the press release.

“We will not stand by and allow the harmful and oftentimes deadly practice of over-prescribing highly addictive drugs to continue unchecked. The FBI will pursue medical personnel who misuse their positions of trust to blatantly disregard others’ very lives for their own financial gain.”