The reason: “The Unwritten 60-Day Rule,” an unofficial Justice Department policy that asks prosecutors to avoid public actions that might influence an election.

Afp Contributor / AFP / Getty Images Former FBI Director Robert Mueller

Tensions are heightened among those watching — and being watched by — special counsel Robert Mueller’s investigation.

Roger Stone is suggesting an indictment against him could be coming — “I’m next on the crooked special prosecutor’s hit list,” he wrote in a fundraising email — and some commentators aren’t disagreeing that that is a possibility. A person whom Mueller’s office believes has information about Stone has been subpoenaed to testify before the grand jury Sept. 7. Several others already have testified. Then, Stone posted a bizarre video earlier this week, disclaiming a story about him that hasn’t been written, then went on a conservative radio show and suggested that Donald Trump Jr. will also get indicted by Mueller. The reason for all of this is in big part because of an upcoming deadline — Sept. 7, 60 days before the election — that isn’t actually a deadline but is informally discussed by some inside the Justice Department as a deadline and thought of by many outside the Justice Department as a deadline. “The Unwritten 60-Day Rule” is how the recent inspector general’s report regarding the department’s handling of the Hillary Clinton email investigation described this rule-that’s-not-a-rule. As described in the report, the rule is that “prosecutors avoid public disclosure of investigative steps related to electoral matters or the return of indictments against a candidate for office within 60 days of a primary or general election.” This has led many to talk and think about the next nine days as the key moment to see what Mueller’s team has pulled together in its investigation into Russia’s efforts to influence the 2016 election and any involvement in those efforts by the Trump campaign and President Donald Trump’s allies. If it’s not actually a rule, then what are people talking about? The written policy, which itself is not even a rule in the sense of being a federal law or regulation, is significantly less specific and less of a directive than people suggest.

Mark Wilson / Getty Images Roger Stone

In at least the past three presidential election years, the attorney general has sent out a two-page memo to all Justice Department employees regarding “election year sensitivities.” The second half of the memo addresses the Hatch Act — the law that prohibits many federal employees from engaging in political activities. The first half of the memo, though, addresses “investigation and prosecution of election crimes,” asserting that “politics must play no role in the decisions of federal investigators or prosecutors regarding any investigations or criminal charges.” Specifically, it continues, “Law enforcement officers and prosecutors may never select the timing of investigative steps or criminal charges for the purpose of affecting any election, or for the purpose of giving an advantage or disadvantage to any candidate or political party. Such a purpose is inconsistent with the Department’s mission and with the Principles of Federal Prosecution.” The only mention of the nearness of an election, however, is not an outright prohibition but instead a request to consult with the Criminal Division’s Public Integrity Section if “faced with a question regarding the timing of charges or overt investigative steps near the time of a primary or general election.” Justice Department spokesperson Sarah Isgur Flores told BuzzFeed News that the most recent of these memos, sent by then-attorney general Loretta Lynch in April 2016, remains operative. She also confirmed that no additional memos have supplemented it since then. So, there’s no rule beyond that, and Mueller can do pretty much what he wants? Not exactly. The “60-day period” is taken seriously by Justice Department officials. As the inspector general’s report noted, “The 60-Day Rule is not written or described in any Department policy or regulation. Nevertheless, high-ranking Department and FBI officials acknowledged the existence of a general practice that informs Department decisions.”

Brendan Smialowski / AFP / Getty Images Former FBI director James Comey

If this all sounds somewhat familiar to you, it’s because we went through this in 2016. The reason for its discussion in the inspector general’s report is former FBI director James Comey’s decision to send a letter to Congress on Oct. 28, 2016, 13 days before the election, announcing that the FBI had reopened the Clinton email investigation. The letter — quickly made public and receiving wall-to-wall news coverage — certainly altered the final days of the election. It was immediately criticized by past senior department officials of both parties who referenced the “60-day period.” Some, including Nate Silver, have argued that the letter was “probably” … “enough to change the outcome of the Electoral College.” While the inspector general’s report did not delve into the letter’s effect on the election, it did criticize the decision to break with department norms. “Although there is no codified ’60-day rule,’” the inspector general’s report noted, “Comey acknowledged that he has consistently adhered to this ‘take no action’ norm in the past.” In response to Comey suggesting he faced “two doors” — “speak” and “conceal” — the inspector general’s report countered that the doors were actually “follow policy/practice” and “depart from policy/practice.” “His task was not to conduct an ad hoc comparison of case-specific outcomes and risks,” the report concluded. “Rather, the burden was on him to justify an extraordinary departure from these established norms, policies, and precedent.” The inspector general’s office concluded that Comey’s action ran counter to departmental norms and that the burden was on him to justify violating those norms. What does that mean for now and for Mueller? As we approach the midterm elections, and coming just months after that report was issued, there’s no reason to think Mueller — and Deputy Attorney General Rod Rosenstein, who oversees Mueller’s investigation — wouldn’t adhere to that norm. All of this doesn’t mean Mueller will shut down his operation after that date passes — the second trial of Paul Manafort, for example, is set to take place during the 60-day period — it just means he’s unlikely to take any steps that would be seen as a new “public disclosure” during the 60-day period. After the election, of course, the rule (however one looks at it) would no longer apply — and public actions could start up again.

It is always possible, though, that something could happen that Mueller and Rosenstein would feel “justif[ied] an extraordinary departure” from those norms during the 60-day period. Former Obama White House counsel Bob Bauer discussed what those possibilities could be in a recent post at Lawfare, writing that Mueller might feel comfortable proceeding within the 60-day period if he has an indictment ready that “implicates Americans for the first time in active collusion with Russians or expands still further on what is known about the Russian cyberattacks on the US electoral process.”

Mueller and Rosenstein are, however, aware of the burden they would face to prove they’d met the standard — particularly given the far-reaching political effects, from Trump and administration officials and campaign staffers on down to Senate and House races, of any potential action in Mueller’s investigation. As such, and while it’s not a rule, it is nonetheless likely that any “public disclosure” that would be seen as “affecting any election” — as in, a significant indictment or any decision related to the oft-discussed Mueller–Trump interview — that is going to happen before the midterm elections will come in the next few days.