Four months after Dist. Atty. George Gascón sent a request to law enforcement agencies across Los Angeles County, more than 40 departments have yet to provide his office with names of officers who have histories of dishonesty and other misconduct that could affect their credibility in court.

Prosecutors have a constitutional duty to give defense attorneys evidence that could cast doubt on a defendant’s guilt or reduce a potential sentence, including information that could diminish the credibility of prosecution witnesses. That obligation stems from a landmark 1963 U.S. Supreme Court case, Brady vs. Maryland, which requires prosecutors to alert defendants to favorable evidence.

“So much of this has been politicized as somehow not supportive of law enforcement because you want to get these records,” said [Loyola Law School professor Laurie] Levenson, a former federal prosecutor. “And that’s just not the case. These records are terribly important to weed out the bad officers and to make sure defendants are having fair trials.”