A doctor accused of prescribing pain killers to three young men who died was ordered Tuesday to stand trial for second-degree murder in the overdose deaths.

Dr. Hsui-Ying "Lisa" Tseng is one of only a handful of doctors nationwide to be charged with murder related to prescription drugs.

The decision by Superior Court Judge M.L. Villar de Longoria to send Tseng to trial came after a three-week preliminary hearing where she was portrayed as the go-to doctor for people seeking drugs.

Young men told of coming to Tseng after using up prescriptions from other physicians. A few testified under grants of immunity.

There was testimony about a total of 12 of Tseng's patients who died of drug overdoses. Only three deaths were charged by prosecutors as solely caused by her prescriptions.

Some patients acknowledged using illegal drugs such as heroin that they did not get from Tseng. She was charged with prescribing Xanax, oxycodone, methadone, Soma, and other drugs.

Authorities allege that Tseng, who operated a storefront medical clinic with her husband in suburban Rowland Heights, wrote more than 27,000 prescriptions over a three-year period. The judge called the amounts "astounding."

Tseng has pleaded not guilty to 24 felony counts and could face 45 years to life in prison if convicted on all charges.

The judge denied a defense request to have Tseng's bail lowered from $3 million to $1 million.

The judge said the results of Tseng's prescription writing should have been reasonably foreseeable to her when her patients started dying in alarming numbers.

"She continued to prescribe these narcotics in high doses even after she was told something was terribly wrong and young men were overdosing and dying," said Villar de Longoria.

The judge cited testimony about one young man who received an opiate prescription, went into the restroom at Tseng's office and overdosed, requiring paramedics to be called.

The judge said Tseng, who took an oath to do no harm, "used her prescription pad to inflict irreparable harm."

Mothers of some of the young men who died sat weeping quietly as the judge gave her ruling.

Outside court, defense attorney Allan Stokke, who argued the murder charge was unsupported by law, said more legal motions will be filed.

"She's ready to continue the battle," he said.

Deputy District Attorney John Niedermann told the judge at the start of the hearing that Tseng knew that three other patients had died after receiving drugs from her in 2007 and 2008.

"It put her on notice that the prescriptions she was providing were leading to deaths," he said.

No charges were filed in those earlier drug overdoses, but the prosecution sought to use them and other deaths as evidence against Tseng.

The preliminary hearing was more extensive than most, with more than 40 witnesses testifying. They included members of law enforcement, the coroner's office, former staff members at Tseng's clinic, expert witnesses, former patients and family members of patients. The prosecution presented 140 pieces of evidence.

Tseng was represented by five attorneys, an indication of the seriousness of the case.

Four of the attorneys presented final arguments, blaming the dead patients for making a willful choice not to follow Tseng's instructions on how to take the drugs.

Some patients added alcohol to the mix, they said, arguing Tseng did not have "a crystal ball" that would tell her they were abusing the drugs. They said she treated her patients in good faith and wanted to relieve their pain.

However, Tseng's receptionist Gloria Rodriguez took the witness stand and described an office crammed with 20 people at a time and 15 waiting in the hallway. When some patients complained about the wait, Rodriguez said Tseng told her, "'They're druggies. They can wait.'"

Tseng, wearing an orange jail uniform and shackles, kept her head down and took notes. She has been in custody since her arrest in March.

In court for every day of the preliminary hearing was April Rovero, whose son Joey died after receiving prescriptions from Tseng. The 21-yearold University of Arizona student drove to California with friends to get the prescriptions in 2009.

The deaths of Vu Nguyen and Steven Ogle also were charged in the case.

April Rovero founded the National Coalition Against Prescription Drug Abuse.

In recent days a delegation of mothers appeared in court wearing protest T-shirts and buttons with pictures of the dead young men.

The judge set Tseng's next court appearance for July 10.