A judge’s finding of systematic misconduct by the Orange County District Attorney’s office is deeply disturbing and indicates that major reforms are needed. Last month, Orange County Superior Court Judge Thomas Goethals disqualified the D.A.’s Office from continuing to prosecute Scott Dekraii, who pled guilty to killing eight people at a Seal Beach hair salon. Unless Judge Goethals’ ruling is overturned on appeal, the California Attorney General’s Office will handle the upcoming proceeding where a jury will decide whether to impose the death penalty on Dekraii.

The disqualification of an entire prosecutor’s office rarely, if ever, occurs. Judge Goethals found that the D.A.’s Office was illegally using jailhouse informants and unconstitutionally hiding the information from defense lawyers, and he concluded that the “District Attorney has a conflict of interest in this case, which has actually deprived this defendant of due process in the past.”

The Constitution limits use of jailhouse informants to gain incriminating statements from another prisoner. Once a criminal defendant is represented by an attorney, the government is not allowed to question the defendant without the attorney being present.

Prosecutors, though, may use incriminating statements by a criminal defendant to a cellmate or others so long as the government did nothing to encourage or procure them.

In the Dekraii case and others, it has been learned that the D.A.’s Office has systematically used jailhouse informants to elicit incriminating statements, including by offering benefits in exchange for information and by taping conversations. This is clearly unconstitutional.

Also, the Constitution requires that prosecutors disclose to defendants any evidence that might be used to show a defendant’s innocence or to lessen a sentence or to impeach a prosecution witness. The rules of professional conduct for lawyers also impose the same requirements on prosecutors. Judge Goethals found that the D.A’s Office was systematically and continually violating this obligation. There also is evidence that sheriff’s deputies lied in court about the program and the frequency of its use.

These are not obscure rules or mere technicalities. These are basic constitutional rights that have been long established. Every law student learns them, and every lawyer knows them. It is why the systematic violations by the D.A.’s Office are so disturbing and why Judge Goethals took the extreme step of removing it from the Dekraii case.

But the wrongdoing by the D.A.’s office goes beyond this practice and this case. At the end of last month, the Orange County Bar Association passed a resolution supporting judicial independence and sharply criticizing the way in which the D.A.’s office has sought Judge Goethals’ removal from many criminal cases.

Under Section 170.6 of the California Code of Civil Procedure, either side of a case may have a judge removed on the grounds that he or she is “prejudiced.” The L.A. Times reported that, according to court records, the D.A.’s office asked to disqualify Judge Goethals in 57 cases since February 2014. Over the three previous years, court records show prosecutors submitted five such requests.

The O.C. Bar Association passed a resolution strongly criticizing this. It explained that “[t]he excessive use of Section 170.6 … can give the appearance of being designed as punitive and retaliatory and going beyond the realm of appropriate criticism.” A D.A.’s office undermines judicial independence when it systematically uses Section 170.6 to remove a specific judge from criminal cases. The message to all judges is that if they draw the ire of the District Attorney’s office, prosecutors will make sure that they no longer can hear criminal matters.

It is truly extraordinary for a judge to remove a D.A.’s office from a case – or for a bar association to pass a resolution condemning one. That both have occurred in the past month is strong evidence of a serious problem.

The burden is on state Attorney General Kamala Harris to conduct a thorough investigation. In fact, a more independent investigation is warranted because there are sufficiently close ties between the A.G. and D.A. offices. Harris should appoint an independent, blue-ribbon commission, with full investigatory powers, to examine the O.C. D.A.’s office. The investigative commission should be given a short timeline, such as four months, to gather information and present recommendations for reform.

Prosecutors have enormous power. Prosecutorial abuses undermine the Constitution and risks the imprisonment, or even execution, of innocent people. The law is clear that prosecutors are to seek justice and uphold the Constitution, not just convictions and sentences. Unfortunately, the Orange County District Attorney’s Office seems to have forgotten this far too often.

Erwin Chemerinsky is dean of the UC Irvine School of Law.