Dr. Robert Henderson, a Dallas orthopedic surgeon, had heard the name of neurosurgeonDr. Christopher Duntschmentioned with alarm before their paths ever crossed.

“It had circulated that he had operated on a good friend of his and made him into a quadriplegic,” Henderson tells PEOPLE.

Another patient of Duntsch’s, a woman on whom he’d operated for a routine herniated disk, “ended up bleeding to death in the recovery room.”

So when the administrator of Henderson’s hospital asked him to evaluate the post-op condition of a third Duntsch patient, “my antennas were up,” he says.

Duntsch was new to the hospital’s staff, and just starting to establish his practice, according to a new Oxygen seriesLicense to Kill, which premieres Sunday at 7 p.m. ET/PT with an episode about Duntsch. (An exclusive clip is shown above.) Henderson learned the third patient had walked in for surgery two days earlier but been unable to bear weight on her legs in the aftermath “and was in excruciating pain,” he says.

Dr. Robert Henderson.Dylan Hollingsworth

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So did Duntsch’s argument with the hospital administration that he be allowed to operate on a patient for a brain tumor despite the fact that the hospital didn’t have the required equipment.

“My first thought as I discovered the gravity of the situation was that this man might not have even been trained as a physician, let alone a surgeon,” he says.

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Henderson urged the hospital to swiftly suspend Duntsch’s privileges, which it did. Henderson then launched his own investigation into the doctor’s background, and found that Duntsch had been suspended during his training for alcohol and drug abuse. Court testimony would later show that behavior had continued.

“I can’t conceive of a way that he wasn’t aware that he was hurting patients,” says Henderson, who eventually took his concerns to the state medical board. “I obviously understand the necessity for due process,” he says. “But I don’t understand procrastination.”

Dr. Randall Kirby

But the failure of one hospital after another to notify a national practitioner databank or the state licensing board allowed Duntsch to continue working without any record of documented discipline that might have stopped him. Patients on whom he continued to operate were unaware of his past.

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“He was a megalomaniac,” says Henderson. “Every patient that I interviewed told me that one of the first things Dr. Duntsch would tell them when they initially met was that he was the best surgeon in Dallas.”

By the time the Dallas County district attorney’s office got involved and brought criminal charges against Duntsch, the prosecutor counted 33 of his surgeries that had gone wrong — and two patients were dead.

License to Killdebuts on Oxygen on Sunday (7 p.m. ET/PT). An exclusive clip is above.

source: people.com