Michael Cohen, President Donald Trump’s former lawyer, has announced his willingness to testify before the House Oversight and Reform Committee and the House and Senate intelligence committees before he enters prison on March 6. Yet he’s also postponed his latest round of congressional appearances more than once, generating irritation and skepticism within the House and Senate. His offer to testify may also be worrying Special Counsel Robert Mueller and other prosecutors who may view congressional proceedings as interfering with their prosecutions. But those types of concerns haven’t derailed congressional inquiries in the past, and shouldn’t now. Still, Congress must proceed carefully to avoid missteps with this high-profile witness.

As someone who spent nearly 30 years as a congressional investigator and advocate for bipartisan, fact-based inquiries, I’ve been watching the Congress-Cohen faceoff with interest.

Cohen is a potential gold-mine of information on a wide array of topics: payoffs that buried negative stories during the presidential campaign; the role of American Media, Inc. and its chief executive David Pecker; negotiations during the 2016 presidential campaign to build a Trump Tower in Moscow; the story behind $500,000 paid to Cohen by Russian oligarch Viktor Vekselberg; Russian purchases of Trump real estate; any Russian-related investments by Trump family members including in Rosneft, the Russian oil company; Trump tax practices; and more. Congressional investigators can also try to get to the bottom of why Cohen lied during his prior testimony to Congress.

Aside from what he has to say, the committees are likely also interested in any evidence not currently in their possession: the Cohen emails, memos, and correspondence — not to mention telephone recordings — taken into custody by federal prosecutors.

Perhaps of equal interest to the committees is Cohen’s knowledge about the inquiry being conducted by Mueller. Possible questions include what issues and evidence seem to be of primary interest to the Mueller team, and the extent and nature of Cohen’s cooperation.

The Supreme Court has held that Congress has the right to conduct wide-ranging investigations to carry out its constitutionally-assigned functions. Those functions include: (1) acting under the separation of powers doctrine to serve as a check on possible executive branch abuses; and (2) obtaining information needed by Congress to make informed decisions about such matters as legislation, appropriations, treaties, and sanctions. Both provide Congress with a clear constitutional basis to take testimony from Cohen and subpoena materials in his possession.

Among the policy issues at stake are whether a media company misused its First Amendment rights to influence a presidential election and, if so, whether such conduct should be restricted or prohibited; whether a foreign government influenced the 2016 elections and, if so, how election security should be strengthened; whether the President’s business interests are affecting his foreign policy decisions — including on Russian sanctions — and, if so, what new conflict of interest or ethics rules may be necessary; and whether the President is using legal means to avoid paying U.S. tax and, if so, whether his tax returns should be made available for analysis with tax reforms to follow.

Those and other policy questions warrant congressional inquiry even though contemporaneous criminal, counterintelligence, and civil investigations are taking place. Many — perhaps most — congressional investigations move forward at the same time as executive branch proceedings.  The executive branch typically focuses on violations of law, while Congress typically focuses on policy. Past examples include Watergate, Enron, the 9/11 terrorist attack, and the financial crisis inquiry. During the course of those cases, multiple criminal, intelligence, civil, administrative, and congressional inquiries advanced at once, each with different aims.

Law enforcement often worries that congressional hearings will damage their efforts by, for example, generating inconsistent statements by key witnesses, exposing previously hidden evidence, or enabling lawbreakers to coordinate their defenses. But congressional committees can work with sensitivity to avoid those problems. In addition, prosecuting wrongdoers may not always be the paramount concern. Jailing the Watergate burglars, for example, turned out to be less important than the fact-finding that led to the president’s resignation, major campaign and ethics reforms, and legal rulings finding that the president was subject to the rule of law.

A key question here is whether the committees can obtain useful information from Cohen — without jeopardizing ongoing criminal, counterintelligence, and other investigations — to further Congress’s separation of powers and informational objectives.

Many members of Congress are justifiably leery of a convicted felon who’s pled guilty to crimes laced with fraud and deception. At the same time, it’s clear he has first-hand information on matters of national importance, and he claims to be willing to cooperate. So it makes sense for Congress to see what it can learn from him.

To maximize the committees’ chances to obtain useful information, a three-step process, carried out on a bipartisan basis, offers a practical path forward.

First, the committees need to obtain copies of the Cohen materials provided to — or seized by — prosecutors. Since his lawyers conducted an extensive review of those materials, they know what prosecutors have and, as a matter of cooperation, can authorize prosecutors to give copies to Congress. The committees can then review and digest the information to deepen their understanding of the facts. Hopefully, committee efforts to obtain that information are already underway.

Second, with the documents in hand, the committees should depose Cohen behind closed doors, perhaps in one or more joint sessions. A closed-door transcribed interview is standard congressional practice prior to a hearing. Investigators can explore both the facts and the evidence, including the extent to which documents verify what Cohen has to say. A non-public setting will enable congressional investigators to examine his views in depth, test his claims, and evaluate the strength of the evidence.

The alternative of interviewing Cohen first in a public hearing is asking for trouble.  Members of Congress won’t know what he will say and won’t be ready to contradict dubious statements with facts and evidence. That two committees have already announced their intent to proceed first in a non-public setting is a welcome sign that they intend to proceed carefully. Better yet would be for all three committees to endorse that course of action.

While the media may object to an extended closed inquiry, its interest in public proceedings shouldn’t determine congressional decisionmaking about the pace of the Cohen inquiry, especially when closed-door interviews may result in public testimony that is more accurate and reliable.

The subsequent third step is public hearings. Using information gleaned from prior depositions, committee members would be able to ask informed hearing questions and challenge suspect statements. The ensuing dialogue would enable other members of Congress, the media, and the public to reach their own judgments about Cohen’s veracity.

Executing the three-step process won’t be quick or easy. Document review and depositions may take months, especially if done in a bipartisan manner that allows both sides of aisle to ask all the questions they think are relevant. But that is exactly the type of process needed if the two sides are to have any chance of reaching consensus on the facts. Both Democrats and Republicans will need to see the same evidence at the same time if their understanding of the facts is to mature together.

Luckily, at the moment, there appears to be no reason to rush. Recent rule changes now allow House committees, like their Senate counterparts, to rely on staff to conduct the lengthy interviews needed to get to the bottom of the Cohen information.

In addition, Cohen’s prospective date for entering prison isn’t a cutoff. Convicted felons can be interviewed while incarcerated, and can leave prison to testify on the Hill. During my time with the Senate Permanent Subcommittee on Investigations, for example, we conducted several prison interviews and called prisoners to testify before Congress, including Antonio Giraldi, a convicted money launderer who testified before the Senate in 1999. So the game isn’t over when the prison gates close.

With appropriate sensitivity to ongoing criminal, counterintelligence, and other investigations, congressional proceedings will not interfere with law enforcement efforts. The long, successful history of parallel executive and legislative branch investigations demonstrates that both efforts can advance at the same time.

Michael Cohen offers Congress a potentially significant source of factual information on multiple policy fronts, including those where the stakes – safeguarding our democracy – could not be higher.  Here’s hoping the congressional committees take the time to get it right.

Image: Michael Cohen, President Donald Trump’s former personal attorney, arrives at federal court for his sentencing hearing, December 12, 2018 in New York City. (Photo by Eduardo Munoz Alvarez/Getty Images)