One thing you can’t say about Robert Johnson is that he has shied away from positions that irritate cops and their allies. Personally opposed to capital punishment, the Bronx district attorney in 1996 withstood incredible public pressure and refused to seek the execution of a brutal cop-killer. In 1999, his office charged four members of the NYPD’s street crimes unit with murder in the killing of an unarmed Amadou Diallo. Last year Johnson pursued indictments and convictions against cops accused of fixing parking tickets in exchange for favors.

And now comes word that his office will stop prosecuting cases of alleged criminal trespass at public housing complexes unless the arresting officer submits to an interview to make sure the offense actually happened.

According to the Times, “Prosecutors quietly adopted the policy in July after discovering that many people arrested on charges of criminal trespass at housing projects were innocent, even though police officers had provided written statements to the contrary.”

Criminal trespass arrests are among the byproducts of the NYPD’s stop-and-frisk policy, which City Limits reported on this summer with support from The Investigative Fund. We looked at the busiest precinct for stops — the 75th in East New York, Brooklyn — and scrutinized the patrol sector within the precinct where the most stops occurred, Sector E. There were 4,628 stops in Sector E in 2011. These generated 123 arrests. A quarter of the arrests were for criminal trespass.

Citywide, criminal trespass was the seventh most commonly heard charge at criminal court arraignments in 2011, and ranked fifth among crimes for most non-arraignment summonses. Concerns about criminal trespass enforcement actually pre-date the uproar over stop-and-frisk. There have long been complaints that police busted people for trespass who were visiting friends, or even walking through their own building but not holding identification.

However, it’s important to note that some residents in high-crime areas wanted this kind of aggressive enforcement. A friend of mine who for many years lived on a block of Valentine Avenue in the Bronx that was a high-traffic drug market says the only thing that kept drug dealers out of his hallway was the tactic of vertical sweeps the cops used to look for trespassers. Just a couple weeks ago, a woman living in public housing told City Limits that she was often scared to enter her lobby because a broken front door meant non-residents could be hanging out inside. Many of the criminal trespass arrests that occur outside of public housing happen in “clean halls buildings” where a landlord has signed an affidavit permitting cops to enter and search for folks who shouldn’t be there; it’s one way property owners responded to tenants’ calls to clean up sketchy buildings.

What will the impact of the Bronx DA’s policy be? That’s unclear. The number of criminal trespass arrests in the Bronx was already falling before the DA announced their policy change. Very few stop-and-frisks result in arrests, for trespass or anything else, so it’s unclear whether this will affect the number of people stopped.

Will it mean more crime? Earlier this summer the tabloids screamed that the NYPD’s reining in cops amid the political outcry over stop-and-frisk was contributing to increased bloodshed. So far this year, crime in the Bronx — where trespass arrests are down 38 percent — is up about 3 percent. In Queens, where, according to the Times, “trespass arrests actually rose considerably,” crime is up 4 percent this year.