PORTLAND, Maine (AP) — A Maine doctor who runs an addiction treatment center has been convicted on multiple counts of illegally distributing opioids including oxycodone, hydromorphone and fentanyl.

Dr. Merideth Norris, 53, of Kennebunk, Maine, was found guilty in federal court Friday of distributing the opioids at her practice. According to court documents, she did so without a legitimate medical purpose and knowing that some patients were battling an opioid addiction. She prescribed the drugs, according to court documents, even after patients failed drug tests or were known to redistribute the drugs in the community.

A federal jury convicted Norris on 15 counts of distributing controlled substances and she faces up to 20 years on each count.

Prosecutors accused Norris of putting her patients’ safety at risk, according to the Portland Press Herald, and failing to heed warning signs like failed drug tests among her patients or advisories from insurance companies about her prescribing of dangerous combinations of opioids and other drugs.

Her defense team tried to make the case that Norris helped patients reduce their medications and that the charges ignored the complexity of treating people who were addicted to opioids and struggled to find a doctor, the newspaper said.

Norris could not be reached for comment and her recovery center was closed Saturday.

Norris has long faced scrutiny for her prescribing practices, including from pharmacists who refused to fill prescriptions she wrote. Walmart pharmacies also issued a “central block,” or a nationwide ban, on filling prescriptions written by Norris.