On Friday, Michael Cohen skipped a federal court hearing reviewing his emergency claims surrounding attorney-client privilege. Instead, he made a public showing of cigar-smoking nonchalance with friends at a Manhattan hotel. That same day, President Trump pardoned Scooter Libby and also reportedly had a phone conversation with Cohen. Could Trump’s pardon have signaled something to Cohen, and might that be why he looked so brazenly unfazed?

Maybe Cohen was putting on a good show, or maybe he is simply not a good lawyer, because one thing is clear: Any of Trump’s pardons (or firings) wouldn’t be likely to save Cohen, just as they wouldn’t be likely to save Paul Manafort or Michael Flynn. That’s because, as I’ve written before, presidential pardons only apply to federal charges, and there are ways for federal prosecutors to craft their charges so as to leave the door open for state charges that wouldn’t violate double jeopardy in case of pardons or firings. Just to be safe, though, New York state should immediately rewrite its double jeopardy laws to ensure that Trump won’t be able to use pardons to help his personal attorney and fixer evade justice.

First, here is a partial list of the New York state criminal statutes that Cohen may have violated, based on a survey of news reports.

1. Bank fraud: Cohen is reported to have allegedly misrepresented to banks the purposes of accounts created to pay off women, claiming they were real estate accounts. These practices and others might implicate New York Penal Law under Article 190.

2. Conspiracy to conceal federal campaign finance violations: This charge would ordinarily be subject to federal prosecution, but Cohen may have made false filings and false statements—to banks or to public officials—as part of his efforts to cover up allegations of Trump affairs in the midst of the 2016 presidential campaign. New York state law criminalizes a broad range of such false statements under NYPL 210.45 (a Class A misdemeanor punishable by a year in jail): “A person is guilty of making a punishable false written statement when he knowingly makes a false statement, which he does not believe to be true, in a written instrument bearing a legally authorized form notice to the effect that false statements made therein are punishable.” This criminal provision also may be implicated if Cohen made false statements to state officials. If state prosecutions start investigations and interviews, Cohen will have to tell the truth about these events, and more, or face New York’s family of perjury statutes.

3. Obstruction of justice and defrauding the government: Rick Gates pleaded guilty to such a conspiracy charge under Title 18 U.S.C. 371. Similarly, New York has a provision (NYPL 195.20) making “defrauding the government” by a “party officer” a felony. Michael Cohen is currently a national deputy finance chairman of the Republican National Committee. NYPL 195.05 makes “obstruction of governmental administration” a misdemeanor.

4. Did Cohen participate in any meetings with Russians as part of a conspiracy to engage in election fraud (collusion)? If so, New York Election Law Sections 17-150(2), 17-152, and 17-154 could all come into play.

5. Bribery: In January 2017, Cohen met with Ukrainian politician Andrii Artemenko and Felix Sater in New York City to discuss a plan to lift Russian sanctions, and he delivered their written proposal to then–national security adviser Michael Flynn. Might this have been part of a quid quo pro arrangement of personal value to Cohen, who has significant financial ties to Ukraine? What about Michael Cohen’s work in Russia and in New York in 2015 and 2016 to establish Trump Tower Moscow? If so, he may have violated New York bribery laws.

6–10. Cohen may also be implicated in the same state money laundering (NY Penal Law 470), state tax fraud, state larceny, conspiracy in computer hacking (NYPL 156), and trafficking of stolen goods that Manafort might also be implicated in.

This list could go on and on, but these core charges should be plenty to make Cohen more nervous than he’s been looking in recent days.

At the same time, though, a New York statute also presents a potential obstacle to such state prosecutions. At Slate, I have written before about how New York’s double jeopardy laws could have protected former Trump campaign chairman Paul Manafort from a state prosecution. I also noted that Mueller—who has reportedly coordinated with New York’s attorney general office—appears to have withheld specific charges against Manafort to avoid this problem. That same hurdle could pose a problem for prosecutors in the Southern District of New York, who are handling Cohen’s case.

Here’s the key provision: New York’s Criminal Procedure Law 40.20 states, “A person may not be twice prosecuted for the same offense.” The issue is that New York defines prosecution broadly. Section 40.30 notes that this applies to charges:

filed in a court of this state or of any jurisdiction within the United States, and when the action either: (a) Terminates in a conviction upon a plea of guilty; or (b) Proceeds to the trial stage and a jury has been impaneled and sworn or, in the case of a trial by the court without a jury, a witness is sworn.

The New York statute does not allow a state prosecution to follow a federal prosecution (“a court of any jurisdiction within the United States”) for the same core facts. So if federal prosecutors start a trial on all of the potential charges against Cohen, and then Trump pardons him, state prosecutors will not be able to come to the rescue. Similarly, if Cohen pleads guilty to some federal charges, and then gets pardoned for them, New York state prosecutors will then have fewer avenues and less leverage.

As discussed, Mueller has already demonstrated a strategy for circumventing this problem in the case of Manafort by bringing some charges but not all possible charges, and in the case of Flynn by getting narrow guilty pleas limited to certain facts.

A New York statute also presents a potential obstacle to such state prosecutions.

But this New York statute on double jeopardy might still create problems down the road, depending on the approach of SDNY and depending on who else all of these investigators put in their crosshairs. Because Trump could still attempt to pardon other figures who have been or may be implicated in a more narrow set of crimes—and because we don’t yet know the strategy for dealing with Cohen—New York state legislators should revise or repeal these extra double jeopardy protections to eliminate the possibility of an obstructive pardon.

There are admittedly questions about whether such a repeal would be a good idea, dealing with both substantive fairness and procedural rules.

First, fairness: Double jeopardy is a legitimate problem. Allowing federal or state prosecutors to take multiple cracks at a defendant is problematic, and it is unfair to let prosecutors use initial prosecutions to test weak cases, work out strategy, or just harass citizens. But we have a principle of “dual sovereignty” because state governments and the federal government have separate but overlapping interests, and each serves as a federalism backup when the other system breaks down. The issue of possible Trump self-serving pardons would be one such example, but one can imagine other system failures that dual sovereignty addresses. What if a prosecution starts under one presidential administration, but a new corrupt administration drops those charges on appeal? New York’s statute would prevent the state from being a justice safety net in either circumstance. The best update to New York’s rules would still obviously set a maximum of one state prosecution and one federal prosecution. This rule would be a good way to guarantee no repeat harassment by any set of prosecutors, but also allow ways for the state to address possible system breakdowns at the federal level.

Second, procedure: There’s real danger in changing laws just to target a specific set of individuals. If New York changes its rule, would the defendants be able to claim that the changes are retroactive ex post facto laws, changing criminal liability after the fact of the crime’s commission? Article I, Section 10 of the Constitution prohibits ex post facto laws, because they unfairly impose criminal liability without advance notice of criminality.

In Collins v. Youngblood, the Supreme Court has held that the Constitution prohibits federal or state governments from depriving a defendant of a “defense” that had been available when the offense was committed. However, the definition of defense under the Ex Post Facto Clause is narrower than the colloquial understanding of the term. In order to violate the Ex Post Facto Clause, the defense that had been removed must relate to the legal definition of the offense or the punishment imposed for a violation, rather than a more formally procedural protection. A change to this New York statute would be a procedural change, not a change to substance or sentence.

Also, it’s to good to keep in mind that lawyers think about double jeopardy in terms of when jeopardy “attaches.” It does not attach or start with the crime, the investigation, or the filing of charges. It attaches with a guilty plea or a trial commencing.

There’s another constitutional question: The Constitution prohibits bills of attainder, laws that target specific individuals. The Supreme Court has adopted a three-part test to determine if the legislative enactment constitutes a bill of attainder: Does it (1) impose a punishment, (2) specify the affected persons, and (3) lack the protection of judicial process? A law that generally lessens double jeopardy protections would not impose a punishment, would not specify any individuals, and would retain core judicial process.

All of that said: These changes need to be made quickly to address this current set of pardon troubles.

A change in New York law that would allow successive charges against individuals who had already pleaded guilty or started trial in federal court would face valid Ex Post Facto Clause challenges. However, defendants who plead guilty or start trials in federal court after such changes in New York law had been passed would be unlikely to win such challenges.

Manafort, Flynn, and Cohen face so many charges on so many different sets of facts that Mueller and federal prosecutors probably can continue without needing such a change—although it would help them. Other co-conspirators, however, might be guilty of a smaller set of crimes. A change in New York law now would make sure to counteract the potential for faithless abuse of pardon and firing power. And even if New York’s legislature were to simply make this rule change on prospective deterrent basis, it would be a wise response to the unfortunate lessons of the Trump era, balancing the opposing concerns about repeated prosecutions, self-dealing pardons, and protecting federalism’s fail-safes in case of presidential corruption.