Dark details emerge on United Airlines doctor's criminal past

Troubling details have emerged about the Kentucky doctor who was dragged off a United Airlines flight at O'Hare International Airport on Monday.

Dr. David Dao was charged with 98 felony drug counts in 2003 for illegally prescribing and trafficking painkillers such as hydrocodone, OxyContin and Percocet, according to TMZ.

According to a criminal complaint filed against him, Dao also allegedly solicited sex from a male patient in exchange for drug prescriptions.

Dao, who attended medical school in Vietnam in the 1970s, was eventually convicted on six felony counts of obtaining drugs by fraud and deceit.

Dao was placed on five years of supervised probation in January 2005, although he surrendered his medical license one month later, according to the Courier-Journal.

The Kentucky Board of Medical Licensure allowed Dao to resume his practice in 2015, but only under certain conditions.

See people on social media react to United Airlines kicking Dao off his flight: