The Supreme Court on Friday limited how prosecutors can use an obstruction statute against former President Donald Trump as well as hundreds of cases tied to the Jan. 6, 2021, attack on the Capitol.

The 6-3 decision overturned the interpretation of the law allowed in the case against one defendant, Joseph Fischer, which could pave the way to similar challenges from defendants in other cases stemming from the attack. The statute, originally passed in 2002 as part of a broader law dealing with financial crimes, threatens a 20-year prison sentence for anyone who “corruptly” obstructs, influences or “otherwise” impedes a proceeding before Congress.

The opinion, written by Chief Justice John G. Roberts Jr., found that the law can only apply to records, documents or objects for use in an official proceeding, not a defendant’s conduct. Roberts wrote that allowing the statute’s “otherwise” phrase to cover conduct aside from documents would “largely obviate the need for that broad array of other obstruction statutes” in federal law.

Prosecutors said Fischer trespassed into the Capitol and was involved in a physical confrontation with law enforcement, the opinion states. He was charged with seven crimes overall, including forcibly assaulting a federal officer, entering and remaining in a restricted building, and engaging in disorderly and disruptive conduct in the Capitol.

But allowing the obstruction charge “would intrude on that deliberate arrangement of constitutional authority over federal crimes, giving prosecutors broad discretion to seek a 20-year maximum sentence for acts Congress saw fit to punish only with far shorter terms of imprisonment,” Roberts wrote.

Special counsel John L. “Jack” Smith also used the statute to buttress two of the four charges against former President Donald Trump in the case alleging he masterminded an effort to overturn the 2020 presidential election. In court filings in Washington, Smith has differentiated the charges against Trump, saying it related to his effort to submit false slates of electors to Congress.

Justice Ketanji Brown Jackson filed a separate opinion supporting the majority’s interpretation and arguing that it was “highly unlikely” that Congress meant to “establish a first-of-its-kind general federal obstruction crime” when it passed the law in 2002.

“Here, it beggars belief that Congress would have inserted a breathtakingly broad, first-of-its-kind criminal obstruction statute (accompanied by a substantial 20-year maximum penalty) in the midst of a significantly more granular series of obstruction prohibitions,” Jackson wrote.

Justice Amy Coney Barrett, joined by Justices Sonia Sotomayor and Elena Kagan, argued that the majority reached its decision because the justices “simply cannot believe that Congress meant what it said” in the law.

“[The law] is a very broad provision, and admittedly, events like January 6th were not its target. (Who could blame Congress for that failure of imagination?)” Barrett wrote. “But statutes often go further than the problem that inspired them, and under the rules of statutory interpretation, we stick to the text anyway.”

Barrett wrote that a straightforward application of that law would include Fischer’s conduct, as he joined the mob that disrupted Congress during the constitutionally mandated counting of Electoral College votes on Jan. 6, 2021.

In Fischer’s case, the trial judge initially dismissed the charge, finding that the statute should not apply to rioters who stormed the Capitol and disrupted the Electoral College count. The U.S. Court of Appeals for the District of Columbia Circuit reversed the judge, holding in a 2-1 decision that the statute could apply to congressional proceedings, not just documents.

Following Friday’s decision, the case now heads back to the D.C. Circuit, where it will likely be further fought over under the new standard.

Some Republican members of Congress signed on to a brief that backed the more limited interpretation of the law. House Judiciary Chairman Jim Jordan, R-Ohio, praised the decision in a statement Friday.

“The Supreme Court’s decision is an affirmation of the rule of law and a reminder that Congress — not out of control prosecutors — writes the law,” Jordan said.