Prosecutors sought to have 90 convictions thrown out following a review of arrests involving a New York City detective indicted on perjury charges after being accused of lying about drug deals that never happened. On Wednesday a Brooklyn District Attorney vacated dozens of cases investigated by the detective at two separate hearings.

Joseph Franco, 48, has arrested thousands, many on drug charges, throughout his two-decade career as a detective with the New York Police Department. He was charged with perjury, offering a false instrument for filing, and official misconduct in Manhattan in 2019 after authorities say he lied about alleged drug deals that video footage showed never occurred.

“I cannot in good faith stand by convictions that principally relied on his testimony,” Brooklyn District Attorney Eric Gonzalez said Wednesday.

He added that the mostly low-level cases Franco investigated between 2004 and 2011 should be vacated because of the pending charges against him. “I have lost confidence in his work,” Gonzalez said.

Franco was fired from the police department in April 2020.

While Franco’s former colleagues, including a lieutenant in the department who acted as his supervisor and a fellow detective, characterized him as “one of the best detectives,” who had a “sixth sense” for locating drug dealers, charging documents against Franco indicate that while working undercover in February 2017 and May 2018, he falsely claimed to to have witnessed individuals engaging in drug transactions, although security camera footage contradicted his claims in each of the four arrests included in the indictment.

Franco “touched thousands of cases throughout New York City, and we may never know the full extent of the damage he caused and lives he upended,” said Tina Luongo, an attorney with the Legal Aid Society’s criminal defense practice.

Brooklyn Criminal Court Judge Keisha Espinal vacated more than 50 drug convictions involving Franco on the morning of March 31, and dozens more were scheduled to be vacated later that afternoon. The majority of the 27 felony and 63 misdemeanor convictions, resulted from guilty pleas. The 27 people convicted on more serious drug charges spent between six months and a year in prison.

“The damage is done at the point of arrest,” said Luongo, “They likely had bail set on them, spent time at Rikers Island, lost jobs, were separated from their families — no matter what happens, those harms were done.”

The three convictions that resulted from his alleged misconduct have been vacated.

“The district attorney has determined that under these circumstances the vacature of a drug related conviction serves the interest of justice, preserves limited resources, enhances public safety and strengthens trust in the criminal justice system,” Assistant District Attorney Eric Sonnenschein said at the March 31 hearing.

Defense attorneys and prosecutors involved in the cases weren’t aware of Franco’s misconduct at the time of the criminal proceedings, since he wasn’t charged until years later.

“The conviction review unit at the district attorney’s office has not found that the defendants’ convictions were based on fabricated evidence or that the defendants are innocent,” Sonnenschein said.

Franco’s attorney, Howard E. Tanner, said in a statement that the decision to vacate the cases involving his client was “premature.”

Tanner added, “This shocking and highly publicized decision has created a toxic atmosphere that is prejudicial to Mr. Franco’s constitutional right to the presumption of innocence and a fair trial by an impartial jury.”

Franco has pleaded not guilty to the charges against him. The criminal case is pending.