It is hard to pinpoint exactly when people who appeared in front of Judge ShawnDya L. Simpson noticed something wrong.
There were times when the judge would come to court late, leave early, or not show up at all. Her demeanor became inconsistent, and she treated lawyers and others in her courtroom in a way that was “erratic and at times intemperate,” state officials said.
It was unusual enough that the State Commission on Judicial Conduct opened an investigation into Judge Simpson, who has served in three boroughs in her 16-year career. That inquiry ended on Monday, with the judge’s announcement that she had agreed to retire in October after acknowledging to the commission that she has an advanced case of Alzheimer’s disease.
“This is as sad a situation as I have encountered in over 40 years of judicial ethics enforcement,” Robert H. Tembeckjian, the administrator of the commission, said in a statement.
The commission did not say when Judge Simpson, 54, first began to have symptoms of the degenerative brain disease or whether it had affected any of her rulings. She has been on a medical leave of absence for the last year.
Before she took the leave, Judge Simpson had handled three high-profile exoneration cases linked to questionable tactics used by the former Brooklyn homicide detective Louis Scarcella.
The commission’s inquiry, which began in mid-2019, focused not on Judge Simpson’s decisions but on what investigators described as her unpredictable behavior and claims that she was “frequently absent from court.”
The state commission discovered during the course of the investigation that Judge Simpson had taken a medical leave of absence for “an undisclosed condition” in August 2019, court papers said.
Four months later, the commission informed Judge Simpson that it was also investigating a complaint that she was “suffering from a physical or mental disability that prevented her from properly performing her judicial duties.” Then in March, the commission informed Judge Simpson in its own formal complaint that she “should be retired from judicial office.”
It is rare for a judge to step down from the bench because of a cognitive condition, a situation that Judge Simpson seemed to acknowledge in a statement she released on Monday.
In the statement, Judge Simpson, who was raised in Canarsie, Brooklyn, said she had expected her retirement to come much later in life and described her tenure on the bench as a “childhood dream come true.”
“I came from a ZIP code that doesn’t often spawn the kind of life, family and career I have been blessed to enjoy,” she said. “My life has been a little Black girl’s American dream.”
Before she was appointed to the bench in 2004, Judge Simpson served as a bureau chief in the Brooklyn district attorney’s office, where she supervised more than 40 people and was responsible for the prosecution of thousands of criminal cases.
She began her judicial career as a civil court judge and, after running unsuccessfully for the city’s Surrogate’s Court, was elevated to serve as an acting justice in the State Supreme Court in Manhattan in 2011, handling criminal trials.
In 2015, Judge Simpson was transferred to the State Supreme Court in Brooklyn where, in one of her most noted cases, she threw out the conviction of John Wayne Bunn, who spent 17 years in prison for the 1991 murder of an off-duty corrections officer.
In her decision, Judge Simpson cited a history of wrongdoing by Detective Scarcella, who had worked on the case as well as several others that were eventually reversed. In a dramatic courtroom scene, Judge Simpson held Mr. Bunn’s hand from the bench as he wept in gratitude.
The state investigation did not indicate when Judge Simpson, who finished her career in the Bronx, received her diagnosis. But it noted that her lawyers gave the commission medical records in February showing that she was suffering from Alzheimer’s at “an advanced level uncommon to a person of her age.”
“The commission sought to balance its responsibility to ensure public confidence in a capable judiciary with compassion for Judge Simpson and her family over her heartbreaking Alzheimer’s diagnosis,” Mr. Tembeckjian said in his statement.
Judge Simpson’s family declined to comment on the details of her illness. In a separate statement released on Monday, her husband, Jacob Walthour Jr., a hedge fund executive and the chairman of the board of Ebony magazine, said the “early, sudden and hollowing effects” of Judge Simpson’s ailment “serve as a reminder to us all to live life passionately and with purpose every day.”
Some lawyers who appeared in front of Judge Simpson in the weeks and months before she took her leave raised questions about whether her condition might have affected her decisions from the bench.
Last August, the same month she stepped down, the judge was considering the case of Nelson Cruz, a man who was requesting a new trial after spending more than 20 years in prison for a murder that he said he did not commit. Detective Scarcella had handled part of the investigation.
When Judge Simpson ran through the list of reasons for why she was denying the request, Mr. Cruz’s lawyer, Justin Bonus, was visibly upset, according to a video of the hearing.
Mr. Bonus informed Judge Simpson that she seemed to have misunderstood the evidence in the case — among other things, mistakenly suggesting that a prosecution witness who testified at the hearing had testified at trial. “This is wrong,” Mr. Bonus told the court.
Then Judge Simpson left the bench abruptly without an explanation. When she came back more than an hour later, she stood by her decision to return Mr. Cruz to prison. Again she appeared mistaken about the evidence, this time wrongly suggesting that the prosecution witness had testified for the defense.
“I had never seen anything like it,” Mr. Bonus said in an interview.
In June 2018, a prosecutor with the Brooklyn district attorney’s office asked Judge Simpson to step aside in a rape case after she took the unorthodox step of personally interviewing a potential witness at the trial in private and outside the presence of lawyers, a violation of administrative rules.
Joseph Sieger, a lawyer for the defendant, Francisco Castro Rosas, said that he had no recollection of the incident. But prosecutors said that Mr. Rosas’s case was ultimately transferred to another judge. Mr. Rosas later pleaded guilty to the charges.
Several people who worked closely with Judge Simpson said they had seen no indication that her judgment was impaired before she took her leave last year.
Lisa Schreibersdorf, the executive director of Brooklyn Defender Services, said in an email that Judge Simpson “has been one of the smartest and best judges we have ever had” and “was an incredibly fair prosecutor.”
Michael Farkas, who worked with the judge at the Brooklyn district attorney’s office and later served as the president of the Kings County Criminal Bar Association, said Judge Simpson was smart, empathetic and well-liked as a jurist.
“I never had any indication, professionally or socially, that she was slipping,” Mr. Farkas said.