This article first appeared on the blog Impeachable Offenses.

One of the biggest open questions about the Russia investigation is what Robert Mueller might do if he were to find legal wrongdoing on the part of the president of the United States. A problem for Mueller, sometimes acknowledged but more often ignored or glossed over, is that he has no independent authority to secure an indictment against a sitting president.

A still more fundamental problem, at least if one hopes that any criminal behavior committed by Trump and uncovered by Mueller might result in the former’s removal from office, is that even a felony conviction would not eject the president. Only impeachment performs that trick. So, if Mueller concludes that Trump did commit a crime and he wants Congress to know about it, he needs a way to present his conclusions to Congress. Unfortunately, he has no independent authority to release the results of an investigation that doesn’t produce an indictment.

However, there are at least two ways Mueller can force the DOJ’s hand, or at least make it easy for Congress to do so. Both approaches would comply fully with Mueller’s limited mandate and the department’s internal rules. First, Mueller could prepare a report and recommendation that Trump be indicted after he leaves office and trust that Congress would find means of obtaining the report. Alternatively, Mueller could recommend immediate indictment, fully expecting rejection of that recommendation, and rely on the technicalities of the Justice Department’s own rules to ensure transmission of his recommendation and reasons to Congress.

Let’s begin with a quick refresher on the limitations of Mueller’s office:

• Mueller, as a special counsel rather than an independent counsel, has only the authority granted any United States attorney. He remains subject to the chain of command of the Justice Department. In ordinary circumstances, he would answer to the attorney general. Because Jeff Sessions has recused himself from this matter, Mueller answers to Deputy Attorney General Rod Rosenstein.

• As special counsel, Mueller is subject to the “rules, regulations, procedures, practices and policies of the Department of Justice.” And while the regulations accord him an unusual degree of autonomy, his superior, here Rosenstein, can overrule him if he proposes doing something contrary to DOJ policy.

Mueller’s appointment letter also empowers him to prosecute any crimes discovered in the course of his investigation.

The policy of the Department of Justice, expressed in several legal opinions issued by the Office of Legal Counsel, is that federal prosecutors may not indict a sitting president. An OLC opinion is not law in the sense of binding anyone outside of the DOJ itself. But it does bind DOJ employees. Therefore, if Mueller were to propose indicting Trump, that proposal would be contrary to current department policy. Deputy Attorney General Rosenstein could, and almost certainly would, order Mueller not to present the indictment to a grand jury. Mueller would have to follow that order. Failure to do so would be an entirely proper ground for removing him.

Given this internal restriction on special counsel Mueller’s authority, one might ask whether Mueller has the power even to investigate whether Trump has committed any crime. The answer is plainly yes. The letter commissioning Mueller charges him with investigating coordination between Russia and the Trump campaign and any crimes, such as obstruction, committed in an attempt to interfere with that investigation.

Mueller’s appointment letter also empowers him to prosecute any crimes discovered in the course of his investigation. The only question is whether DOJ rules restrict this authority in the case of a president.

Internal DOJ policy precludes prosecuting a president while he is in office. It does not claim that presidents cannot be prosecuted. Indeed, any such claim would be untenable inasmuch as Article 1, Section 3 of the Constitution specifically provides that persons impeached “shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.” At a minimum, this means that a president may be indicted after he leaves office.

Mueller’s appointment letter granting him prosecution authority does not require that he prosecute the crimes he discovers immediately. Accordingly, if the Mueller investigation yielded evidence that Trump committed a crime, Mueller would be entirely within his mandate to prepare a report setting out his findings and recommending that Trump be indicted as soon as he leaves office.

The difficulty with this option from the perspective of those hoping to base an impeachment inquiry on Mueller’s work is that he has no independent authority to release such a report to Congress or the public. It seems quite likely that a Justice Department under increasing pressure from the White House would make every effort to keep the report secret. On the other hand, there is nothing in the special counsel regulations or any applicable law that requires secrecy in such a case. If it were to become known that such a report existed, someone in Congress could request it. And if Democrats gained control of either house of Congress in 2018—a precondition for impeachment in any case—they would also gain the power to subpoena the report.

Suppose, however, that Mueller were to decide that Trump has committed crimes and that Congress should know of that conclusion promptly. Suppose further that Mueller were not disposed to rely on the vagaries of midterm elections and still less to wait for the expiration of the Trump presidency. In that case, there is another path.

The DOJ’s special counsel regulations provide that if a special counsel proposes an action that the DOJ rejects because it would be “inappropriate or unwarranted under established Departmental practices,” then the responsible party at the DOJ must notify both the chairs and ranking minority members of both the House and Senate Judiciary Committees of the special counsel’s proposed action and an “explanation” of the reason for rejecting that action.

Hence, Mueller would be operating entirely according to protocol if, while not actually presenting an indictment to a grand jury, he recommended to Rosenstein that Trump be indicted. He would, of course, realize that doing so would contravene an existing OLC opinion. However, there would be nothing untoward if he concluded, with the concurrence of the superb appellate lawyers on his staff, that the OLC opinion should be reconsidered. OLC conclusions are subject to internal re-evaluation all the time.

Of course, we can fairly predict that Mueller’s arguments, however learned, for changing DOJ policy on this point would be rejected. But rejection of Mueller’s recommendation for indictment on the ground that it contravened “established Departmental practices” would trigger the mandatory report to Congress required by the Code of Federal Regulations, Title 28, Section 600.9. Et voila! Members of Congress from both parties, and in due course, the public, would know that Mueller believed Trump committed a crime.

As clean as this second approach seems, there are two potentially significant flies in the ointment. First, the mandatory reporting requirement of the Code of Federal Regulations, Title 28, Section 600.9 is triggered only “upon conclusion of the Special Counsel’s investigation.” One reading of this language is that it applies only after the special counsel completely wraps up all his responsibilities. Deploying that interpretation, a Trump-influenced Justice Department could justify withholding congressional notification until Mueller finished not only investigating, but trying, all pending cases. Given that at least Paul Manafort and Rick Gates remain untried, trials could delay things a long while. Alternatively, the reporting requirement could be read as arising once the purely investigative phase of Mueller’s work ends, without regard to the resultant litigation. But that interpretation would carry the day inside the department only if the person making the call were principled, courageous, and more committed to institutional integrity and the rule of law than to protecting the president.

Regardless of how the reporting requirement were read, if Mueller thought it central to his mission that his conclusions about Trump be reported to Congress expeditiously, he could abandon or fast-track pursuit of the smaller fry targets, close up shop, and insist that the department’s own rules be followed.

The second potential obstacle to this gambit is one not of law but personal psychology. Mueller, by reputation a man who operates strictly by the book, might not be willing to formally propose indicting Trump knowing that the proposal would be summarily rejected as violating existing DOJ policy.

I like to think that, as both an undoubted patriot and a career public servant not unaccustomed to harnessing formalism to larger ends, Mueller would not be averse to engaging in a bit of bureaucratic Kabuki theater in the interests of revealing Trump’s conduct to Congress while there is yet time to do something about it.

We shall see.