The bar association opened an investigation of Durham County District Attorney Mike Nifong last March shortly after the case began.
"It's hard for me to imagine how he can be effective as an advocate, with either the court or a future jury, when he has ethics charges pending against him ... concerning his conduct of this very same case," said Joseph Kennedy, a University of North Carolina law professor.
The North Carolina bar filed the ethics charges Thursday, accusing District Attorney Mike Nifong of violating four rules of professional conduct by making misleading and inflammatory comments about the athletes under suspicion.
Kennedy said Nifong should recuse himself, but added that the judge overseeing the case could also order his removal. The ethics charges carry penalties that range from admonishment to disbarment.
The bar said it opened a case against Nifong on March 30, a little more than two weeks after a 28-year-old woman hired to perform as a stripper at a lacrosse team party said she was gang-raped.
The rape charges against the three students were dropped earlier this month.