Attorney General William Barr is expected to release a redacted version of the Mueller report to the public today. Morning Edition Host Joe Mathieu spoke with Northeastern Law Professor and WGBH Legal Analyst Daniel Medwed about what to look for in the nearly 400-page report. The transcript below has been edited for clarity.

Joe Mathieu: Let's start at the beginning. The attorney general says the report shows the president was not guilty of colluding with Russians during the investigation. That was in his summary a couple of weeks ago. And Daniel, we have all learned that the act of collusion is, in fact, not a crime.

Daniel Medwed: That's right. The word "collusion" is really a word that's bandied about by the media. But the crime is the crime of conspiracy. That's when you agreed to commit a crime and someone takes a step in furtherance of that criminal objective, acting with purpose. So we're going to look for evidence of an agreement between Trump, the campaign and the Russians. That's what we need to look for there.

Mathieu: And how specific would that need to be? We hear about the Trump Tower meeting, the Trump Tower in Moscow and so forth. Do you need to actually see language that proves collusion to help him win an election?

Medwed: That's a great question. Not necessarily. It just has to be a tacit understanding that they're coordinating their activities. That's enough to rise to the level of an agreement. But if they're just proceeding on totally parallel tracks and not coordinating, it might not be enough.

Mathieu: Barr also said in his summary that Trump was not exonerated, essentially, on the issue of obstruction of justice. So what will you be looking for to make that judgment when it comes to obstruction today?

Medwed: Obstruction of justice is fascinating. There are more than a half dozen different obstruction of justice crimes in the federal code. It can be a crime to obstruct or impede the progress of an investigation, of a judicial proceeding, [or] of an administrative proceeding. But there's connective tissue between all of them. You have to do two things: you have to act in a way that impedes or influences an official proceeding; and second, you have to do so with corrupt intent. So here's what I'm going to be looking for. There's going to be evidence of actions that impede official proceedings. We know that Trump got involved to stop the investigation of Michael Flynn, for instance. But did he do it with a corrupt intent? And to prove corrupt intent, you need either direct evidence of a corrupt intent — an admission from President Trump — or more likely, circumstantial evidence that creates an inference of a corrupt intent. So I'm going to look at all these behavioral patterns to see [if there is] evidence here that could prove corruption.

Mathieu: So in the case of the firing of James Comey, the FBI director at the time, his comment to NBC that he had Russia on his mind, would be that type of evidence?

Medwed: Absolutely. And that, in my view, is direct evidence. So I think there could be evidence, conceivably, of obstruction.

Mathieu: We know it will be heavily redacted. What purpose though, as someone who's dealt with a lot of redacted legal documents over your career, does that serve? Who does it protect? And I wonder, is there any limit to redacting a legal document, or could they blackout this whole thing?

Medwed: That’s going to be a big piece of this. I think it's going to look like a color-coded Mad Libs document. So many things are going to be redacted that it might be actually hard to read in spots. So there are four different categories of redacted material that I anticipate appearing here, and they're all going to be color coded different colors so we'll know which category is locked out and which one isn't. So [here are] the four categories: First, grand jury material. Under federal law — Federal Rule of Criminal Procedure 6(e) — you can't disclose anything from a grand jury; second, classified information that relates to national security; third, information about an ongoing investigation; and fourth, information that relates to privacy interests of third parties. The rationale there is that we don't want to disclose sensitive information [or] jeopardize important things. It's that third category that's really interesting. If we see a lot of color that correlates with ongoing investigations, we know there's a lot more going on behind the scenes and we can expect things.

Mathieu: But it sounds like, basically, everything you want to see will be redacted.

Medwed: I think so. I mean, I'm cautiously optimistic that we'll learn something from this report, but I fear that a lot is going to be kept out due to the Justice Department lawyers redacting it.

Mathieu: Is this going to be the roadmap to impeachment that many Democrats think?

Medwed: It's possible. The rule for an impeachable offense is less stringent than the rule for charging someone with a crime or convicting someone beyond a reasonable doubt. It's really in the eye of the beholder. So I imagine House Democrats, in particular, looking at this could find an impeachable offense. So it could supply that roadmap.