Misconduct by prosecutors in Southern California has led to dozens of criminal convictions being overturned on appeal — that’s the finding from a new study by Harvard Law School’s Fair Punishment Project, which looked at court rulings on prosecutorial misconduct across the country.

These are not cases of errors, but of willful and serious misconduct, which can include the use of fabricated evidence, introduction of false testimony, and withholding of evidence that points to innocence.

The worst record in the state, based on population, belongs to the Orange County District Attorney’s Office, with Los Angeles County second and Riverside County fifth.

Because it’s rare and difficult for a convicted defendant to prove in court that a prosecutor engaged in misconduct, the relatively high rate of reversals is troubling.

The Harvard study reports that in the six years from 2010 to 2015, Los Angeles County had 78 findings of misconduct and 22 reversals of convictions in which misconduct was a factor. Orange County had 24 findings of misconduct and seven reversals. Misconduct by prosecutors was a factor in four reversals and 32 cases in Riverside County; nine cases and two reversals in San Bernardino County.

A 1976 Supreme Court decision gave prosecutors absolute immunity from lawsuits seeking damages for willful misconduct. Even police officers have only qualified immunity. But a divided court in Imbler v. Pachtman held that it was enough of a check on prosecutors that they could be sanctioned by their professional organizations.

That’s happening now to former L.A. County prosecutor Carmen Trutanich, facing charges from the State Bar of California of suppressing evidence and failing to correct false testimony in the 1985 murder trial of Barry Glenn Williams. Last year, a judge reversed Williams’ conviction and death sentence, citing misconduct by Trutanich.

While Williams spent 30 years in prison, Trutanich went on to become city attorney of Los Angeles.

Is there too much incentive to obtain convictions at any cost, and too little punishment for misconduct?

U.S. Ninth Circuit Judge Alex Kozinski has suggested doing away with absolute immunity for prosecutors.

That’s a good place to start.