Hsiu-Ying "Lisa" Tseng, 42, is charged with three counts of second-degree murder -- among other felony counts -- in the drug overdose deaths of Vu Nguyen, 29, of Lake Forest, on March 2, 2009; Steven Ogle, 25, of Palm Desert, on April 9, 2009; and Joseph Rovero III, 21, a University of Arizona student from San Ramon, on Dec. 18, 2009.
Tseng is the first doctor accused of murder by the Los Angeles County District Attorneys Office over the prescribing of drugs.
Additionally, Tseng is charged with one felony count of prescribing drugs using fraud, and 20 felony counts of prescribing drugs without a legitimate purpose.
Tseng, who has pleaded not guilty to all the charges, remains behind bars in lieu of $3 million bail.
If convicted as charged, she faces a possible maximum state prison term of 45 years to life.
Tseng opened a storefront medical office in Rowland Heights in 2005.
The Drug Enforcement Administration (DEA) launched an investigation in 2008 after a pharmacy reported overlapping customers.
The DEA alleges that Tseng wrote more than 27,000 prescriptions at her medical clinic in three years -- at a rate of 25 per day -- with minimal questions.
OxyContin, Vicodin, Xanax and Valium were all unlawfully distributed by Tseng out of a Rowland Heights office, according to a DEA report.
One of the alleged victims, Joseph Rovero, was just months away from graduating college when he overdosed on a cocktail of prescription drugs.
"He felt that because he got them from a doctor, it wasn't like buying illegal drugs on the street," his mother, April Rovero, said.
The families of other potential victims have also spoken out. Bruce Stavron's son, Matt, died from an overdose when he was 24.
The San Clemente motocross racer is one of 10 young men who died after overdosing on powerful narcotics prescribed by Tseng, the Los Angles Times reported.
"Within 24 hours of him seeing her, he was dead," Bruce Stavron said.
Tseng, called a "Dr. Feelgood" by District Attorney Steve Cooley, has settled wrongful death lawsuits with five different Southern California families.
"Deaths from overdoses of prescription drugs now outnumber deaths from traffic accidents in the United States," Cooley said in a written statement. "Enough is enough."
"They're violating the law by prescribing drugs for no legitimate medical purpose to otherwise healthy individuals for the sole purpose of the patient getting high," Cooley said. "Those victims die while the doctor gets rich."
Tseng's attorneys say that her patients hid their motives, mixing their meds and ignoring warning labels.
They claim that in multiple cases, the patients crushed and snorted pills and combined them with alcohol and street drugs.
Her attorneys say Tseng cared deeply about her patients, and is looking forward to her chance to prove her innocence in court.
The DEA suspended her license to write prescriptions in 2010 and the Osteopathic Medical Board of California said Tseng voluntarily surrendered her medical license.
Her husband, also a physician, continues to operate the clinic, Advanced Care AAA Medical.