In the wintry darkness 23 years ago on a back street in Williamsburg, Brooklyn, a jewelry thief fleeing a botched robbery panicked and shot a Hasidic rabbi in the head.

Four days later, the rabbi, Chaskel Werzberger, an Auschwitz survivor, died of his wounds. Even in the New York City of 1990, as homicides crested at 2,245, the murder stirred grief and outrage...Forty detectives worked the case, soon led by the swaggering, cigar-chewing Detective Louis Scarcella. Working closely with an influential Satmar rabbi, Detective Scarcella arrested a drug-addicted, unemployed printer named David Ranta. Hasidic Jews surrounded the car that carried the accused man to jail, slapping the roof and chanting, “Death penalty!”

Mr. Ranta was convicted in May 1991 and sentenced to 37.5 years in maximum-security prison, where he remains to this day.

He is almost certainly not guilty.
Mr. Ranta could walk free as early as Thursday. In the decades since a jury convicted him of murder, nearly every piece of evidence in this case has fallen away. A key witness told The New York Times that a detective instructed him to select Mr. Ranta in the lineup. A convicted rapist told the district attorney that he falsely implicated Mr. Ranta in hopes of cutting a deal for himself. A woman has signed an affidavit saying she too lied about Mr. Ranta’s involvement.

Detective Scarcella and his partner, Stephen Chmil, according to investigators and legal documents, broke rule after rule... At trial, prosecutors acknowledged the detectives had misbehaved but depicted them as likable scamps...