A Queens judge Thursday morning dismissed 46 convictions, with some of the convictions being 20 years old.

Queens District Attorney Melinda Katz asked a judge to dismiss the convictions after former NYPD Detective James Donovan admitted to lying under oath.

“We cannot believe in law enforcement, that we never make mistakes, that things don’t happen,” Katz said in an interview with NY1.

According to Queens prosecutors, in 2021, Donovan testified under oath that he found a loaded gun on a suspect during an arrest, but later admitted the testimony was false.

Prosecutors dismissed the gun charges in that case and then decided to take a closer look at some of the other cases Donovan offered testimony on.

Katz said there were 46 criminal cases where Donovan “was the main witness in the prosecution.”

Queens prosecutors then worked with the Legal Aid Society.

“Our investigators fanned out through the city, went through databases and tracked down people to tell them their cases were getting dismissed,” Elizabeth Felber, head of Legal Aid’s Wrongful Conviction Unit, explained.

The convictions were vacated after arrests made between 2004 and 2011, mostly for misdemeanor crimes, “although some people did jail time because of these convictions,” Felber said.

After taking office in 2020, Katz established the first Conviction Integrity Unit for the Queens district attorney’s office. To date, the unit has vacated 148 convictions.

“On a personal level, it gives me great satisfaction to know that our office is not only prosecuting those that that are violent or doing things that need to be prosecuted, but also that we’re looking back at past convictions,” Katz told NY1.

Donovan was a still a detective with the NYPD when questions first surfaced about his testimony. He is no longer with the department.

When NY1 reached out to the Detectives’ Endowment Association for a comment, the union declined to comment.