LOS ANGELES (KRON/AP) – A prosecutor says even after several patients died of overdoses, the Southern California doctor now charged in their deaths continued to pass out prescriptions for powerful painkillers.

Los Angeles County Deputy District Attorney John Niederman told jurors in opening statements Monday that Dr. Hsiu-Ying “Lisa” Tseng deserves to be convicted of second-degree murder in the deaths of three of her patients.

Tseng has pleaded not guilty. Her attorney, Tracy Green, says the deaths were not Tseng’s fault.

Tseng is among only a handful of doctors nationwide to be charged with murder related to prescription drugs. Prosecutors say she pass out prescriptions for powerful painkillers in appointments that lasted as little as three minutes.

The Drug Enforcement Administration says Tseng wrote more than 27,000 prescriptions over a three-year period starting in January 2007 – an average of 25 a day.