Federal authorities issued a scathing report Thursday finding OC District Attorney Todd Spitzer’s office has failed to thoroughly review “systematic” violations of constitutional rights by prosecutors and sheriff officials in an illegal jailhouse informant program.

The informants scandal – which happened under Spitzer’s predecessor, Tony Rackauckas – caused at least a half dozen convictions for murder and other serious crimes to be overturned or dismissed from 2007 to 2016. Courts ruled that sheriff officials and prosecutors illegally used informants and hid evidence from defendants and the court.

The misconduct also caused an Orange County Superior Court judge to kick the entire Orange County DA’s office off of prosecuting the deadliest mass killing in county history after Scott Dekraai shot and killed eight people in a Seal Beach nail salon in 2011.

“The Orange County District Attorney’s Office and the Orange County Sheriff’s Department operated a [jail] informant program that systematically violated criminal defendants’ Sixth Amendment right to counsel and Fourteenth Amendment right to due process of law,” federal Justice Department officials wrote in a news release.

“Even now, almost six years after the Dekraai recusal ruling, OCDA has failed to undertake a sufficient inquiry into the scope of the custodial informant program in Orange County,” the report states, calling for an independent body to examine the issue.