This photo provided by the Dallas County Sheriff’s Department shows Christopher Duntsch. (Dallas County Sheriff’s Department via AP)

“I am ready to leave the love and kindness and goodness and patience that I mix with everything else that I am and become a cold blooded killer.”

It was this e-mail, sent on Dec. 11, 2011, that marked Christopher Duntsch’s transformation from a promising young neurosurgeon to a “danger to patients” accused of purposefully botching surgeries, authorities say.

The e-mail was presented along with other new evidence Monday at a hearing about the Texas doctor’s bail. Duntsch is charged with five counts of aggravated assault for allegedly mishandling spinal surgeries, and one count of injuring an elderly person, according to the Dallas Morning News.

[Ex-con posing as plastic surgeon left patient with deformed penis, police say]

Several people were severely injured on Duntsch’s operating table, local media have reported, and at least two died during procedures that aren’t normally dangerous. It’s not clear which of these incidents Duntsch is being charged for.

“It’s a completely egregious case,’’ Leigh Hopper, then head of communications for the Texas Medical Board, told The Dallas Morning News in 2013. “We’ve seen neurosurgeons get in trouble but not one such as this, in terms of the number of medical errors in such a short time.”

Duntsch arrived in Dallas in 2010 to start a neurosurgery practice. In the course of the next three years he would work at several different hospitals, earning infamy for his haphazard surgical technique wherever he went, according to the Texas Observer. His colleagues described him in the harshest superlatives: “worst surgeon I’ve ever seen,” “sociopath.”

“I couldn’t believe a trained surgeon could do this,” Robert Henderson, another surgeon at Dallas Medical Center, where Duntsch performed several operations, told the Observer. “He just had no recognition of the proper anatomy. He had no idea what he was doing. At every step of the way, you would have to know the right thing to do so you could do the wrong thing, because he did all the wrong things.”

In one case, authorities allege, Duntsch operated on his roommate and friend after a night of using cocaine. The man emerged from the operation a quadriplegic. In another, he purposefully left a surgical sponge inside a man’s body. During that surgery, a fellow doctor forced Duntsch to stop operating because of his “unacceptable” technique, the Dallas Morning News reported, citing a search warrant affidavit.

In 2012, Duntsch voluntarily left Baylor Regional Medical Center of Plano, where he had surgical privileges, after a woman he was operating on reportedly bled to death, according to the Observer. Despite Duntsch’s bad reputation, Baylor hadn’t done anything to stop him from operating elsewhere. Texas law limits hospitals’ responsibility for their doctors’ actions, the Observer explained, and the only entity that can remove a doctor’s license is the Texas Medical Board, which can do so only after receiving and investigating a complaint.

It would take another year for Duntsch’s license to be suspended. In the meantime, a second woman allegedly died on his operating table and at least two others emerged from their surgeries unable to move their legs.

In 2013, Baylor doctor Randall Kirby filed a complaint about Duntsch with the Texas Medical Board after realizing that the doctor was still working in the operating room.

“The TMB must stop this sociopath Duntsch immediately or he will continue to maim and kill innocent patients,” Kirby wrote, according to the Dallas Morning News. “Dr. Duntsch is a clear and present danger to the citizens of Texas.”

After losing his medical license, Duntsch moved to Centennial, Colo., and found work as a bio-medical consultant. Through a series of interviews with the Dallas Morning News in 2014, “he depicted himself  as the victim of a Texas cabal of rival physicians and personal injury lawyers,” the paper reported.

“I’m a well-trained surgeon. I’m a complex spine surgeon. My record is excellent,” he said. “Ninety-nine percent of everything that has been said about me is completely false.”

Duntsch was arrested in July. His attorney told CBS that Duntsch would defend himself on all charges.

But the hospitals where he worked are also facing scrutiny over their treatment of Duntsch. If so many doctors knew that he was, in one colleague’s words, a “clear and  present danger” to patients, why was he allowed to continue operating for so long?

Baylor is now the target of three lawsuits from Duntsch’s former patients, according to the Dallas Morning News, with more likely on the way.

When Duntsch left Baylor and began searching for work at other hospitals, Baylor provided a letter saying that his medical record there was clean, though it was not addressed to any hospital and was not a letter of recommendation, Baylor said.

Duntsch was the subject of a lengthy 2013 Texas Observer article, which concluded that “the real tragedy of the Christopher Duntsch story is how preventable it was. Over the course of 2012 and 2013, even as the Texas Medical Board and the hospitals he worked with received repeated complaints from a half-dozen doctors and lawyers begging them to take action, Duntsch continued to practice medicine. Doctors brought in to clean up his surgeries decried his ‘surgical misadventures,’ according to hospital records. His mistakes were obvious and well-documented. And still it took the Texas Medical Board more than a year to stop Duntsch — a year in which he kept bringing into the operating room patients who ended up seriously injured or dead.”

Sidney Wolfe, a doctor who serves as a senior adviser to the nonpartisan research group Public Citizen, told the Dallas Morning News that hospitals are obligated to stop dangerous physicians. “A hospital that has evidence that a doctor is practicing bad medicine and does not take action has blood on its hands,” he said.