Updated September 5, 2022 at 12:41 PM ET

The first legal step that former President Donald Trump took after FBI agents executed a search warrant at his home last month was to ask a federal court to appoint a special master to review the documents they had seized.

That request spawned a whole new saga, with the Justice Department arguing that such an appointment is not only unnecessary but would "significantly harm important governmental interests, including national security interests."

U.S. District Judge Aileen Cannon granted that request on Monday, setting a Friday deadline for both parties to jointly submit a list of proposed candidates as well as their duties, limits and schedule.

In the meantime, it's worth examining the question: What exactly is the role of a special master in general, and how could the potential appointment of one impact this case specifically?

"A special master really is kind of a fancy name for judge's helper," explains David Cohen, a special master who serves in federal cases including opioid litigation.

He told Morning Edition's Rachel Martin last week that special masters, who are usually attorneys, can be appointed when judges get complex cases — and that Trump's is far from typical. Their conversation has been condensed and edited for clarity.

Interview highlights

What counts as a complex case?

Obviously that's not going to happen when it's a simple car accident, but in a case where the subject matter is complicated — for example, an antitrust case or a patent case — or the case itself is just overwhelmingly large — like the BP oil spill case or national opioid litigation — or even just a case where the parties can't even really say hello to each other without getting into a fight and it just needs a lot of judicial supervision, what a federal judge will sometimes do is appoint a special master just to help the judge oversee the case because there's just a lot to do, and judges have limited judicial resources, limited time.

What qualifications does a special master need?

It's not always an attorney. For example, in a patent case what a judge might need most is somebody who is conversant in the technology at issue, but ... it's usually an attorney. I guess the primary qualification is somebody who can remain neutral, which isn't easy. It's kind of hard to refresh your neutrality every day. You can't come in and be a judge or a special master with an agenda or really kind of wanting one side to win, you need to look at all the facts and the evidence and what the parties are arguing, and apply the law to the facts and come out to what the right result is regardless of who is appearing before you.

Do special masters always try to draw conclusions?

It depends ... if I'm being asked by the judge to provide a report and recommendation on a motion then yes, I'm going to say, "Judge, this is how I think you should rule," and I'll draft an order or a proposed order, or I'll submit my opinion over my signature, which the parties can then accept or appeal to the judge. And in other cases, it's sometimes just being present so that while the parties are arguing you can referee it.

What role could a special master play in Trump's case?

In this case in front of Judge Cannon, it looks like the judge is going to be appointing — if that does happen — appointing somebody who is going to make calls — yes or no; this is privileged, this isn't — [and] submit a report to the parties. The parties would then have an opportunity to object, which is to say, to appeal to the judge, and she would then rule de novo, which means kind of start at the beginning. But everybody knows that for the most part, if the special master knows what they're doing, the judge is going to accept the recommendation.

What makes Trump's case unique?

This is such an unusual case. In most cases where I've been appointed, I'm being asked to oversee discovery, I'm being asked to rule on attorney-client privilege issues. There aren't really any cases where you have the ex-president of the United States having materials taken out of his house and citing not only attorney-client privilege — which is relatively easy, there's all kinds of case law about that — but executive privilege, which has not been the subject of a lot of case law.

Could appointing a special master slow down the Justice Department's investigation?

It's very likely that if Judge Cannon appoints a special master, that the special master's going to have to do a lot of legal research, come to a place of understanding of how to apply the law and look at some pretty unusual facts. So that does have the chance to slow things down. But on the other hand, the judge could provide for a kind of parallel processing, where the review continues by the Justice Department while the special master is reviewing the documents as well.

This interview was produced by Kaity Kline and edited by Simone Popperl.

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