A woman who made millions selling oxycodone, oxymorphone, and morphine out of pain clinics in South Florida and Tennessee was sentenced to 33 years in prison and ordered to forfeit $3.6 million.

Sylvia Hofstetter, 56, of Miami, had been found guilty by a jury in February of Racketeer Influenced and Corrupt Organization (RICO) conspiracy, two counts of drug conspiracy, money laundering offenses, and maintaining drug-involved premises.

“This defendant reaped millions of dollars in personal profits by operating destructive opioid pill mills in multiple states, inflicting lasting harm on multiple communities,” Acting Assistant Attorney General Brian C. Rabbitt of the Justice Department’s Criminal Division said in a news release.

The Justice Department says pill mills owned and operated by Hofstetter and her co-defendants generated more than $21 million in revenue by distributing over 11 million tablets of oxycodone, oxymorphone, and morphine.

Investigators say Hofstetter initially worked at a pill mill in Hollywood owned by three of her co-defendants.

As law enforcement shut down hundreds of pill mills in South Florida, Hofstetter and her co-defendants moved their operations to Tennessee, where a large percentage of the clinics’ opioid-addicted customers lived.

The conspiracy involved four separate clinics in Tennessee, evidence showed.

“Hofstetter’s role in Tennessee was to run the pill mills and ensure that patient volume remained high, thus guaranteeing enormous profits for Hofstetter and her co-defendants,” the Justice Department said in its release. “Once in Tennessee, however, Hofstetter opened her own pill mills in secret from her Florida employers and went into competition against them. Hofstetter personally reaped over $4 million from her role in these offenses.”

The multiagency investigation included work from the FBI’s Miami Field Office and the Hollywood Police Department.