A doctor convicted of murder for prescribing exorbitant amounts of painkillers that left three patients dead could get life in prison.

Dr. Hsiu-Ying "Lisa" Tseng is scheduled for sentencing on Friday.

Her second-degree murder conviction in October is rare for a doctor. It came after a dozen of her patients died.

She was only charged with three killings because other factors were involved in some of those deaths, such as drugs prescribed by other doctors and one possible suicide.

The 45-year-old Tseng was convicted of 20 drug-related counts.

Tseng's lawyer said the doctor had been naive to prescribe so many medications and didn't think her patients would abuse them.

Prosecutors say she prescribed exorbitant amounts of medication to people who didn't need it and ignored signs they were overdosing.