Under United States Supreme Court precedent, it is relatively easy to sue police officers who commit misconduct, but federal law still provides enormous protections to prosecutors. Individual lawyers in district attorneys’ offices enjoy complete immunity from being sued if they make mistakes in the courtroom — even those that lead to wrongful convictions. The unjustly imprisoned in New York are also barred from suing the state unless they can prove conclusively that they are innocent, not just the victims of an unfair trial.
But twice in the past three decades, a New York federal appeals court has protected another way of holding prosecutors liable for their errors: The wrongfully convicted have been allowed to sue both cities and counties, which usually control the budgets of — and issue paychecks for — district attorneys’ offices, which otherwise operate in state court. The suits can be filed only under certain narrow circumstances. Defendants must show that a misstep was related to an administrative matter, like a hiring or a firing, or to an officewide policy, not just to specific prosecutorial decisions. And defendants need to prove that the courtroom errors in their own cases were not only part of a larger pattern of misconduct, but also that the prosecutors knew about the pattern and ignored it.
This spring, however, a federal judge in Brooklyn issued a potentially influential order in a wrongful-conviction case in Queens, saying that under a 2009 Supreme Court ruling, issues related to the “supervision and training” of assistant district attorneys were not administrative matters, but prosecutorial ones, and so the city could not be held accountable for them.
https://www.nytimes.com/2017/10/08/nyregion/holding-prosecutors-accountable-is-hard-it-could-get-harder.html