Investigators say from 2012 to 2017, Dr. Lawrence Choy prescribed almost 1 million pills known as the "Holy Trinity", an addictive deadly cocktail of Oxycodone, Xanax and the muscle relaxer Somo.
Anthony M. DeStefano has been a reporter for Newsday since 1986 and covers law enforcement, criminal justice and legal affairs from its New York City offices.
The three patients died between 2013 and 2016.
"The whole heroin craze right now is because, partly because, of guys like this", said James J. Hunt, special agent in charge of the NY office of the federal Drug Enforcement Administration.
Choy is being charged with second degree manslaughter in connection with their deaths.
Choy moved from NY to Sheboygan, Wisconsin past year after investigators raided his medical practice in Flushing, Queens.
He is charged with giving out illegal prescriptions to 14 patients and allegedly writing over 100 prescriptions for oxycontin in a single month. At their final visits with the doctor, both victims received high-dosage prescriptions for oxycodone and the anti-anxiety medication alprazolam (commonly known by the trade name Xanax).
Officials said the five-year investigation into Choy began when authorities in Pennsylvania began noticing suspicious prescriptions written by Choy being filled there.
However, other patients - including the three who died - had legitimate pain management issues and apparently became addicted to their medications, Brennan said. They say this shift coincided with the filing of tax warrants against Choy for more than $1 million in taxes owed.
Dr. Choy's prescriptions were filed at pharmacies in New York City, upstate New York, Long Island and New Jersey.
Choy was awaiting a court appearance on Thursday. Choy left his practice suddenly in June of 2017, leaving the Flushing office in a state of disarray and moving to Wisconsin.
Choy is also alleged to have prescribed Castillo Percocet in addition to his other regimen. Those three drugs together are known to doctors as the "Holy Trinity", she said. Because all three drug types have the effect of suppressing respiration, the risk of overdose is heightened when they are taken together.
The investigation showed that Choy, "personally observed the patients' physical and mental states deteriorate, while disregarding reports about patients' involvement in accidents, including motor vehicle accidents", the DEA said.