One detective conducted such sloppy eyewitness identification procedures that a judge called the lapses “inconceivable.” Another officer was charged with taking a 14-year-old boy he had arrested on a minor charge to a Staten Island marsh and stranding him there.

A third was once suspended from the force for steroid use and had posted on social media that he was watching “Training Day,” a movie about police corruption, to “brush up on proper police procedure.”

The three officers appear on a blacklist made public for the first time this week by the Brooklyn district attorney, Eric Gonzalez, who says he will no longer call them as witnesses because he has determined they are not credible.

By releasing the list to the public, the Brooklyn district attorney has made it nearly impossible for the officers to do ordinary investigations or make arrests in the borough. The move goes beyond what other district attorneys in the city have done to deal with officers with credibility problems.