It’s rare for prosecutors to bring homicide charges against a physician for a patients death. But the Los Angeles district attorney’s office claimed that the second-degree murder convictions in 2015 of a Los Angeles area doctor were the first against a U.S. doctor for recklessly prescribing drugs,

In 2007 Dr. Hsiu Ying Lisa Tseng, a licensed physician practicing internal medicine and osteopathy, joined Advance Care AAA Medical Clinic in Rowland Heights, a general medical practice operated by her husband.

By 2010, the clinic had developed a reputation as a place where patients could easily obtain prescriptions for controlled substances, including opioids, sedatives, muscle relaxants, and drugs used to treat drug addiction. According to one visitor, the clinic looked “like a parole office” with “drug dealing.”

Beginning in 2008, pharmacists began to refuse to fill prescriptions written by Tseng because the prescriptions raised “red flags”; the patients’ profiles, conduct, and the combination of substances and quantities Tseng prescribed indicated no legitimate medical purpose for writing the prescriptions. When Tseng learned of this, she referred her patients to “mom and pop” pharmacies, which continued to fill her prescriptions.

That same year, law enforcement investigators, including investigators from the coroner’s office, began calling Tseng to discuss the deaths of several of her patients and to apprise her that the patients had died of suspected drug overdoses shortly after obtaining prescriptions from her.

A dozen of Tseng’s patients died, though prosecutors only brought three murder charges because of other factors involved in some of those deaths, such as drugs prescribed by other doctors and a possible suicide. In 2012, Tseng was charged with three counts of second degree murder, 20 counts of unlawfully prescribing controlled substances to patients, and one count of obtaining a controlled substance by fraud.

After a a six-week trial, a jury found Tseng guilty of three counts of second degree murder, 19 counts of unlawfully prescribing controlled substances, and one count of obtaining a controlled substance by fraud. Jurors deliberated for 10 days before reaching the verdicts. The trial court sentenced her to 30 years to life in state prison. Tseng appealed, and the Court of Appeal affirmed in the partially published opinion of People v Hsiu Ying Lisa Tseng.

She claimed on appeal that substantial evidence did not support the murder convictions and that the trial court erred in (1) admitting evidence of six uncharged patient deaths; (2) failing to unseal and quash a search warrant of her financial records; (3) failing to grant a mistrial based on prosecutorial misconduct; (4) reopening closing argument; and (5) failing to apply Penal Code section 654 to the murder conviction sentences.

The Court of Appeal concluded that “None of her arguments are meritorious.”