Brandon Bell/Getty Donald Trump
According to reports from CNN and The New York Times, the unidentified attorney swore in a signed letter to the DOJ in June that there were no more documents of interest at the Palm Beach, Fla. resort, despite the fact that the search returned 11 sets of classified materials.
The reports underscore questions of how many people have legal culpability in the ongoing investigation into Trump's alleged mishandling of classified documents and suspected violation of the Espionage Act.
Meanwhile, Sen. Amy Klobuchar explained the severity of mishandling such materials as she spoke to Andrea Mitchell on Sunday's Meet the Press, especially considering that some of the documents were marked as "top secret/SCI," one of the highest levels of classification.
"As a senator, I know when I look at the classified documents, I've got to go in a special room, Andrea. I can't even wear my Fitbit. You can't bring staff with you," she said. "And that's because these documents not only contain our nation's top secrets but because other countries that will do us harm, do harm to our own citizens, we don't want them to get a hold of them in any way, take photos of them, anything.
Joe Raedle/Getty Mar-a-Lago Club
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"Because they can actually reverse engineer them and figure out who the sources are, what the confidential information is. That's why it is so important that these documents remain in safe locations. And Mar-a-Lago, where you can check out croquet sets and tennis rackets and golf clubs, that's not one of them," Klobuchar, 62, added.
The FBI's search warrant revealed that the investigation into the former president, 76, was in regards to the "removal or destruction of records, obstruction of an investigation, and violating the Espionage Act," according to Politico.
A source previously told The Washington Post that the investigation was in regard to sensitive materials, including those pertaining to nuclear weapons.
The specifics of those documents and whether any were recovered remains unknown, although the report emphasized the potential danger of such classified information falling into the wrong hands.
James Devaney/GC Images Donald Trump
A source with knowledge of the subpoena told PEOPLE, "I can't tell you anything about nuclear documents. But this is why it's important for the subpoena to be made public. The public needs to know what is or is not in that subpoena."
Although Attorney General Merrick Garland said Thursday that the Department of Justice did not intend to publicize the investigation out of respect for Trump's right to privacy, Garland confirmed that he personally approved the decision to seek a search warrant as a last resort in their investigation.
He also noted that Trump's very public statement in response to the search has prompted the DOJ to file a motion in a Florida court to unseal the search warrant and property receipt, making those details available to the public.
Andrew Harnik/AP/Bloomberg via Getty U.S. Attorney General Merrick Garland
"The public's clear and powerful interest in understanding what occurred under these circumstances weighs heavily in favor of unsealing," the motion reads, according to The Post. "That said, the former president should have an opportunity to respond to this motion and lodge objections, including with regards to any 'legitimate privacy interests' or the potential for other 'injury' if these materials are made public."
Garland's speech came as The Wall Street Journal and Newsweek reported that the investigation stemmed from an informant.
RELATED VIDEO: Trump Suspected of Violating Espionage Act, According to Mar-a-Lago Search Warrant
After FBI agents and a senior Justice Department national security supervisor reportedly visited Mar-a-Lago in early June in regards to boxes of classified documents sitting in the property's basement, officials followed up with Trump's lawyer, with instructions to install a stronger lock on the storage room door.
Trump reportedly assured officials that he had no more classified materials, but weeks later, "someone familiar with the stored papers told investigators there may be still more classified documents at the private club."