The longtime New York City prosecutor and former judge who presided over the arraignment of "Son of Sam" killer David Berkowitz will retire earlier than expected, he announced Thursday.

In a statement, Queens District Attorney Richard Brown, who was appointed in 1991, said that although the hoped he would be able to finish out his term in office, “that is not to be.”

It was earlier this year that the 86-year-old, who has been battling Parkinson's disease for the past few years, said he would retire at the end of his term and came to the decision "after careful thought and consideration."

In a statement at that time, Brown said he was "deeply appreciative and humbled to have had the trust and confidence" of voters for so long.

However, Thursday’s announcement revealed that he “intends to resign as District Attorney effective June 1, 2019, the twenty-eighth anniversary of my first assuming this office” citing his “current state of my health and my ongoing health issues.”

Brown also revealed that in the interim, he is designating his Chief Assistant, John M. Ryan “to exercise the powers and duties of the office of District Attorney while I address my health issues. I will continue to work closely with my staff until my retirement to ensure an orderly transition for this office and for the residents of Queens County.”

Brown, a Democrat, ran unopposed six times and become the borough's longest-serving district attorney, but he would have faced competition this time around.

Brown was never a prosecutor until Gov. Mario Cuomo picked him from 14 candidates to replace retiring DA John Santucci.

His tenure has tracked with a precipitous drop in crime in New York City and shifts in how police and prosecutors combat crime. In 1991, there were more than 2,100 homicides in the city. Last year, there were fewer than 300.

Years before a shooting in Ferguson, Missouri, shone a spotlight on police killing unarmed black men, Brown pursued criminal charges against three detectives in the 2006 death of Sean Bell, who was shot leaving a nightclub the morning of his planned wedding.

They were acquitted by a judge, but the police department fired them.

Critics have knocked Brown as a relic of a tough-on-crime era that saw scores of mostly poor minorities put behind bars for low-level quality-of-life offenses.

Brown was born in Brooklyn, but his official biography notes he "has been a lifelong resident of Queens since age five."

Brown, a 1956 graduate of New York University's law school, worked for the state assembly and was Mayor John Lindsay's legislative representative in Albany before being appointed as a criminal court judge in 1973.

Brown served on the bench for 18 years, interrupting his tenure in 1979 to serve as Gov. Hugh Carey's chief legal adviser. He returned to the courtroom in 1981 and is still widely known in legal circles as "Judge Brown."

On Brown's first day as a judge, a defendant pulled out a gun and started shooting in the courtroom. Brown saved himself by dropping to the floor behind his bench.

Brown presided over Berkowitz's arraignment in 1977 under heavy security and intense public interest.

He ordered the then-24-year-old postal worker to undergo psychiatric testing and said that he should be jailed under maximum security conditions, away from other inmates.