IF AMERICANS have learned anything from instances of wrongful criminal convictions, including in capital punishment cases, it’s that the judiciary system is fallible. Among the more effective safeguards against judicial fallibility is transparency, especially when it involves police and prosecutors disclosing pretrial evidence that might help exonerate defendants.

Many states have adopted rules and laws designed to maximize transparency in the interest of ensuring fair trials. Unfortunately, a number of states remain stuck in the past, clinging to trials-by-ambush in which the accused, along with defense lawyers, remain in the dark about witnesses and evidence practically until the moment they are confronted with them at trial.

Virginia is among those states in which police and prosecutors face relatively lax requirements governing material they are required to share with the defense. Mindful of long-standing complaints that trials in the commonwealth too often take place on a tilted playing field, the state Supreme Court impanled a distinguished, highly diverse committee of judges, prosecutors, defense lawyers, police and scholars to consider reforms.

Last month, less than a year after the committee delivered a balanced and detailed set of proposals, the Supreme Court gave its response: Thanks, but no thanks. Giving every indication that it had accorded the issue no serious deliberation, the court dismissed the panel’s work, saying it “declines to adopt the Committee’s recommendations.” The justices then got back to their regular business, which apparently does not include ensuring that criminal trials in the commonwealth are as fair as possible.

The extent of the material that can be withheld from criminal defendants in Virginia is staggering. It includes police reports, statements by witnesses and witness lists. Neither the prosecution nor the defense is required to provide the other with a summary of expert witness testimony it plans to present in court, as is the case in civil trials.

Since commonwealth’s attorneys in Virginia are left largely to their own devices in determining how much information to disclose, there is no uniform set of standards. Some prosecutors, notably many in Northern Virginia, routinely turn over most of the contents of their files to defense lawyers well in advance of trials. Others are far stingier, providing only obviously exculpatory information. The result is a hodgepodge of inconsistency, which the Supreme Court apparently decided was no big deal.

In maintaining the status quo, the court sided with some police and prosecutors, though not all, who argued that victims’ safety could be jeopardized by excessive disclosure of evidence and witness statements. Other prosecutors insisted that more transparency ensured fairer trials — and guilty verdicts that would hold up on appeal.

Mindful of the debate, the committee included in its recommendations ways to exempt the disclosure of sensitive evidence that could endanger victims. But it affirmed, correctly, that the state’s paramount interest is to provide defendants with fair trials.

Rather than choose from among the committee’s proposals, or modify them to suit its preferences and the clear need for reform, Virginia’s Supreme Court let stand a deeply flawed system and ignored the advice of the late U.S. Supreme Court Justice William J. Brennan, who said, “The truth is more likely to come out at trial if there has been an opportunity for the defense to investigate the evidence.”