NASHVILLE, Tenn. -- A Nashville prosecutor has been fired after reports surfaced that he made sterilization of women part of plea negotiations in some cases.

Former Assistant District Attorney Brian Holmgren confirmed Wednesday that he was fired from the Davidson County District Attorney's office. He declined to comment specifically on his dismissal, and officials would not say what prompted his dismissal.

The firing came after The Associated Press reported that the invasive surgery was part of plea bargain talks at least four times in the last five years in child abuse and neglect cases.

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In the most recent case, first reported by The Tennessean, a woman with a 20-year history of mental illness had been charged with neglect after her five-day-old baby mysteriously died. Her defense attorney says the prosecutor assigned to the case wouldn't go forward with a plea deal to keep the woman out of prison unless she had the surgery.

Defense attorneys say there have been at least three similar cases in the past five years, suggesting the practice may not be as rare as people think and may happen more often outside the public view and without the blessing of a court.

Meantime, Davidson County District Attorney Glenn Funk announced Wednesday he discovered a backlog of more than 130 child abuse and child sexual abuse cases that had never been handled, the Tennessean reported.

Holmgren worked in the department responsible for the unresolved matters, some of which were more than ten years old, according to the newspaper.

Sterilization coerced by the legal system evokes a dark time in America, when minorities, the poor and those deemed mentally unfit or "deficient" were forced to undergo medical procedures that prevented them from having children.

"The history of sterilization in this country is that it is applied to the most despised people -- criminals and the people we're most afraid of, the mentally ill -- and the one thing that that these two groups usually share is that they are the most poor. That is what we've done in the past, and that's a good reason not to do it now," Paul Lombardo, a law professor and historian who teaches at Georgia State University, told the AP.

Funk, a former defense attorney who took over the office in September, he recently ordered lawyers in his office not to seek sterilization by defendants. He said he hadn't heard of it happening before but didn't ask.

Funk said people could be ordered to stay away from children, and the state wouldn't have to resort to such invasive measures.

"The bottom line is the government can't be ordering a forced sterilization," Funk said.

However, such deals do happen.

In West Virginia, a 21-year-old unmarried mother of three agreed to have her tubes tied in 2009 as part of her probation after she pleaded guilty to possession with intent to distribute marijuana.

And last year, a Virginia man who fathered children with several women agreed to undergo a vasectomy in exchange for less prison time in a child endangerment case.

Forced sterilization came up in a different way in California last year, when Gov. Jerry Brown signed a bill that banned state prisons from forcing female inmates to be sterilized. The law was pushed through after the Center for Investigative Reporting found that nearly 150 female prisoners had been sterilized between 2006 and 2010. An audit found that the state failed to make sure the inmate's consent was lawfully obtained in every case.

The most recent Nashville case involved Jasmine Randers, 36, who had been under court supervision for mental illness when she left her home state of Minnesota. She gave birth in West Memphis, Arkansas, then fled a homeless shelter to come to Nashville, said her attorney, assistant public defender Mary-Kathryn Harcombe.

Court records show Randers reported awakening in a motel, where she'd slept in a bed with the baby, only to find the child unresponsive. She reportedly called a taxi two hours later and took the child to a local hospital, where the infant was pronounced dead.

There was no sign of injury, and the cause of death was undetermined.

Police later learned that in 2004, Randers stabbed herself in the stomach while pregnant, though the fetus was not harmed. She told investigators that it happened when she fell down the stairs while cutting fruit.

Holmgren was once a senior attorney with the National Center for Prosecution of Child Abuse and serves on the international advisory board of the National Center for Shaken Baby Syndrome. He has been both praised and fiercely criticized for his aggressive courtroom tactics on behalf of children.

Harcombe said he previously asked that another client agree to be sterilized in order to get a plea deal. She refused and it didn't become part of the plea deal reached in that case.

Nashville defense attorney Carrie Searcy told the AP last week that Holmgren asked that two of her clients who gave birth to children who tested positive for drugs undergo sterilization. Neither did, Searcy said, because both women had already undergone the procedure.

Assistant public defender Joan Lawson, who also supervises other attorneys, said she also had been involved in cases in which a prosecutor had put sterilization on the table. Lawson said it was typically not an explicit demand, was not an everyday occurrence and was made off the record. Lawson said she refused the idea and resolved her cases without sterilization.

"It's always been more of 'If your client is willing to do this, then I might be inclined to talk about probation,'" Lawson said.

This time, when Holmgren insisted Randers undergo sterilization to avoid prison, Harcombe complained to his boss. The district attorney took over the case, and Randers was not sterilized. The prosecutor agreed Randers was mentally ill, and she was institutionalized after being found not guilty by reason of insanity.

"Any time a woman is given a choice between prison and this surgery, that is inherently coercive, even in cases where there is no mental illness," Harcombe said.