BANGOR, Maine — A local woman charged with murder in connection with the stabbing death of her boyfriend last year pleaded not guilty by reason of insanity Friday at the Penobscot Judicial Center.

Gail Judd, 53, of Bangor pleaded not guilty last year to intentional or knowing murder in the death of Michael Drouin, 47, on Feb. 22, 2012, in her Court Street apartment.

The plea entered Friday does not replace the original plea of not guilty, but is in addition to it, according to her attorney, Jeffrey Silverstein of Bangor.

“She entered this plea so we can pursue a not-criminally-responsible defense,” Silverstein said in a telephone interview after Judd entered the new plea.

The attorney also said that his client has undergone several psychiatric and medical evaluations. One of the things discovered while Judd was being evaluated last year at the Riverview Psychiatric Center in Augusta is that her liver is failing.

That condition causes too much ammonia to be in her system, which in turn puts Judd into states of delirium, Silverstein said. He speculated Friday that Judd may have been in such a delirious state when she allegedly stabbed Drouin.

Efforts to reach Assistant Attorney General Andrew Benson about the case were unsuccessful early Friday afternoon. It is the practice of the Maine attorney general’s office not to comment on pending cases.

Judd told neighbors she stabbed Drouin in self-defense after he raped her, according to the affidavit filed following her arrest a few days after the stabbing.

She currently is being held without bail at the Penobscot County Jail.

Silverstein said Friday that she was being treated for her liver ailment there.

A trial date has not been set.

If convicted of murder, Judd faces a sentence of between 25 years and life in prison. If found not guilty by reason of insanity, she would be committed to Riverview for an unspecified period of time.