The U.S. Supreme Court limited which defendants accused of taking part in the Jan. 6 Capitol riot can be charged by federal prosecutors for obstructing Congress. The court’s decision also places at least a cloud of doubt about two of the the four felony counts in the election subversion indictment of President Trump.

In an opinion by Chief Justice John Roberts, the court ruled that the government must establish “that the defendant impaired the availability or integrity for use in an official proceeding of records, documents, objects, or other things used in an official proceeding.”

Prosecutors used a key criminal statute to prosecute more than 350 of the most violent participants in the riot.

The statute had two parts. The first part makes it a crime to corruptly alter or destroy documents and records related to an official proceeding. The second part makes it a crime to otherwise obstruct or impede an official proceeding—in this case, the congressional counting of the electoral college ballots.

Roberts said the statute was limited to documents and evidence destruction, and that the word otherwise was not meant to broaden the meaning of the law into a catchall provision.

The vote was 6 to 3 with Justices Amy Coney Barrett joining Justices Sonia Sotomayor and Elena Kagan in dissent.

Writing for the court majority, Chief Justice Roberts said the statute was limited to documents and evidence destruction, and that the word otherwise was not meant to broaden the meaning of the law into a catchall provision.

The case was brought by Joseph Fischer, a former police officer in a township near Harrisburg, Pa., who joined the mob on Jan. 6th, even recording a four-minute cell phone video in which he is heard yelling, “charge,” and is seen in a scrum with police officers.

According to prosecutors, Fischer, in text messages, also threatened violence prior to Jan. 6, including sending a text in which he wrote, “take Democratic Congress to the gallows….can’t vote if they can’t breathe lol.” And when the FBI came to arrest him later, he shouted profanities at the agents and at his own police chief, and he sought to conceal the phone he had used to record events at the Capitol.

The Justice Department maintained that it limited the use of the statute at issue in the case by requiring proof that Fischer and other similarly charged defendants had specifically intended to disrupt the counting of the electoral college ballots and by focusing on elements like a defendant’s preparation for violence, and bringing tactical gear or paramilitary equipment to the Capitol. At oral argument Solicitor General Elizabeth Prelogar told the justices that prosecutors have brought charges against some 1400 defendants in connection with the riot, but that only 350 of those had been charged under the obstruction statute because of the need to prove intent to disrupt the counting of the ballots.

Defendant Fischer’s lawyer, Jeffrey Green, maintained that the reason the government chose to use the statute at all was that it has a maximum penalty of 20 years in prison. Even though nobody has actually gotten such a stiff penalty, he said, for prosecutors it is “a really big cudgel” to use in plea bargaining with defendants.

Friday’s decision has already had consequences. Pending the outcome of Friday’s case, some judges previously allowed a small number of convicted defendants to be released from prison early. Now a larger number will have to be resentenced, retried, or just released.

But while Friday’s decision might intuitively be seen as a devastating blow to prosecutors, a deep dive into the data concludes the effects will be “minimal.” NYU law professor Ryan Goodman is the lead author of the study, published by “Just Security, which relied on NPR’s detailed data base of Jan 6 Capitol riot cases.

Goodman notes that Trump is different from the Capitol rioters because the obstruction charges against him involve efforts to interfere with the electoral college certificates arriving at the desk to be counted on Jan. 6th, and the use of false elector certificates—all of which would seem to fall under the tampering-with-evidence provision of the obstruction statute.

As for the Jan. 6 rioters, the study found that of the 1417 people charged so far in connection with the Jan. 6 invasion, only 346, or 24 per cent, were charged under the obstruction statute. Of that 346, 128 defendants were convicted by a jury of obstruction and another crime, most often another felony, which would still stand.

A different cohort of 48 people pleaded guilty to the obstruction charge, which now goes away. But hovering over all of these pleas is the fact that the plea agreement uniformly included an important caveat: In the event that the conviction were to be “vacated for any reason,” the government reserved the right to prosecute for other alleged crimes that prosecutors had either agreed not to prosecute or agreed to dismiss at sentencing.

Finally, the study, found that until Friday, 71 people were still awaiting trial on the obstruction charge, but more than half are also charged with another felony. While those felonies may not have penalties as severe as the obstruction charge, if the defendants are found guilty of those other crimes, the sentencing judge is permitted to consider the conduct charged in the obstruction case in determining the length of the sentence.

The study’s authors, in addition to professor Goodman, are Georgetown law professor Mary McCord, a long-time federal prosecutor who held a variety of top Justice Department jobs, including chief of the criminal division and acting assistant attorney general for national security; and NYU law professor Andrew Weissmann, also a long-time Justice Department prosecutor, who served as chief of the fraud section, counsel for the FBI, and lead prosecutor in the Mueller investigation of then President Trump.

Of course, Donald Trump, if re-elected, could pardon all the Jan. 6 defendants. He has not committed to doing that yet, though he often refers to Jan. 6 offenders as “hostages” and “patriots.” In his first term he pardoned friends and political allies who were a lot more prominent, including former campaign chiefs Paul Manafort, convicted on corruption charges, and Stephen Bannon, indicted on fraud charges for a build-the-wall fundraising scheme in which he allegedly pocketed $1million.

In addition Trump pardoned his close friend and advisor Roger Stone, indicted on charges of witness tampering, obstruction, and lying to Congress about what he and then-candidate Trump knew about Russian efforts to discredit Hillary Clinton in the 2016 presidential campaign; he pardoned former New York Police Commissioner Bernard Kerik, who pleaded guilty to tax fraud and lying to White House officials; He pardoned Charles Kushner, the father of Trump’s son-in-law, Jared Kushner; the elder Kushner pleaded guilty to 18 criminal counts of tax evasion, witness tampering, and making illegal campaign contributions; and Trump also pardoned his former National Security Advisor Michael Flynn, who twice pleaded guilty to lying to the FBI and then withdrew his guilty pleas.