“Sometimes key information doesn’t get turned over because the prosecutor is breaking the rules, but sometimes it’s inadvertent, like when police don’t give D.A.s the whole file,” she said. “Either way, earlier discovery will give everyone more time to get to the bottom of it.”

For decades, Republicans who controlled New York’s Senate blocked more than a dozen efforts to change the state’s discovery statute. But in last fall’s election, the power shifted to Democrats, who quickly passed not only the discovery law, but measures to curtail the use of cash bail and speed up the pace of trials.

Under the new rules, prosecutors will have 15 days to turn over evidence like police reports, photos, electronic recordings and grand jury testimony, including the names of witnesses. They may request an extension up to 30 days under exceptional circumstances. The law also requires the defense to disclose certain evidence 30 days after prosecutors open their files.

The law empowers judges to hold prosecutors in contempt if they fail to meet the deadlines and to bar the government from using evidence that is not properly disclosed.

The statute also permits prosecutors to request a protective order to shield witness names and information until trial, though judges are not required to grant it.

Perhaps most importantly, the discovery law pegs disclosure deadlines to the arraignment at the beginning of a court case rather than the trial near the end. That shift underscores a reality in New York that holds true across the country: About nine out of 10 cases never make it to trial because most people accept guilty pleas.

Supporters of the changes say people often plead guilty without knowing how strong the prosecution’s evidence is, and each day in jail makes it more likely they will give up.