A New York doctor was convicted of manslaughter after one of his patients died of an overdose and another killed four people during a pharmacy robbery. Dr. Stan Li was also charged and convicted of recklessly endangering six other patients for prescribing controlled substances to known drug abusers.

Li, 60, is an anesthesiologist and pain medicine specialist faces between 5-15 years in prison for the convictions. In total, Li faced 211 counts against him including selling prescription narcotics and falsifying business records. The jury acquitted him of some of the other charges.

New York officials say this is the first case in the country where a physician has been convicted for the death of a patient by unlawfully prescribing pain killers.