CHICAGO --The man dragged from a full United Express flight by airport security officers in Chicago is a Kentucky physician who was convicted more than a decade ago of felony charges involving his prescribing of drugs.
But David Dao's unflattering history quickly became the focus of attention, even though there's no indication that his past influenced how he was treated or that the airline or airport police were aware of his background.
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Dao, who is 69 and lives in Elizabethtown, did not return messages from The Associated Press, which has confirmed that he is the man who can be seen on the cellphone videos taken by other passengers Sunday night at O'Hare Airport.
While screaming can be heard on the videos, nowhere is Dao seen attacking the security officers. In fact, he appears relatively passive both when he was dragged down the aisle of the jet and when he is seen standing in the aisle later saying quietly, "I want to go home, I want to go home."
When the video first emerged Monday, it generated widespread sympathy for Dao and sharp criticism of the airline.
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The chief executive of the airline's parent company initially released a statement saying only that United wanted to talk to the man. But Oscar Munoz later began defending his employees, saying in a letter that the passenger was being "disruptive and belligerent."
That comment certainly suggests that Dao's actions could be examined closely by United and the Chicago Aviation Department, though it remains unclear what role Dao's past might play in those investigations.
On Tuesday, Munoz issued another statement describing the removal as "truly horrific" and offering his "deepest apologies."
"No one should ever be mistreated this way," he said. Munoz pledged to review the company's policies for seeking volunteers to give up their seats, for handling oversold situations and for partnering with airport authorities and local law enforcement.
The company planned to share results of the review by April 30.
According to records from the Kentucky Board of Medical Licensure, Dao went to medical school at the University of Medicine of Ho Chi Minh City in Vietnam, graduating in 1974. He was licensed in Kentucky with a specialty in pulmonary disease.
His legal troubles started in 2003, when his medical license was suspended after an undercover sting operation at a Louisville motel for allegedly writing fraudulent prescriptions.
According to the documents, the licensing board had learned that Dao had become sexually interested in a patient and hired the patient as his office manager. That man later said he quit his job because Dao "pursued him aggressively" and arranged to provide him with prescription drugs in exchange for sex.
Dao was ultimately convicted in late 2004 of several counts of obtaining drugs by fraud or deceit and was placed on five years of supervised probation and surrendered his medical license.
His longtime effort to get his license back was finally successful in 2015, when the licensing board allowed him to practice medicine again.
Airport officials have said little about the Sunday's incident and nothing about Dao's behavior before he was pulled from the jet that was bound for Louisville, Kentucky. Likewise, the Aviation Department has said only that one of its employees who removed Dao did not follow proper procedures and has been placed on leave.
No passengers on the plane have mentioned that Dao did anything but refuse to leave the plane when he was ordered to do so.
Sunday night's confrontation stemmed from a common air travel issue - an overbooked flight. United was trying to make room for four employees of a partner airline, meaning four people had to get off.
At first, the airline asked for volunteers, offering $400 and then when that did not work, $800 per passenger to relinquish a seat. When no one voluntarily came forward, United selected four passengers at random.
Three people got off the flight, but the fourth, a man who said he was a doctor and needed to get home to treat patients on Monday, refused.
Three men, identified later as Aviation Department security officers, got on the plane. Two officers tried to reason with the man before a third came aboard and pointed at the man "basically saying, 'Sir, you have to get off the plane,'" said Tyler Bridges, a passenger whose wife, Audra D. Bridges, posted a video on Facebook.
One of the security officers could be seen grabbing the screaming man from his window seat, across the armrest and dragging him down the aisle by his arms.
Other passengers on Flight 3411 are heard saying, "Please, my God," ''What are you doing?" ''This is wrong," ''Look at what you did to him" and "Busted his lip."
"We almost felt like we were being taken hostage," Bridges said. "We were stuck there. You can't do anything as a traveler. You're relying on the airline."