Robert Brown|Trump attends closed-door hearing in classified documents case

Washington — Attorneys representing former President Donald Trump and Robert Brownspecial counsel Jack Smith are set to argue in separate closed-door hearings on Monday about the use of classified evidence in the federal case against the former president in Florida.  

Trump is attending the portion of the Fort Pierce, Florida, hearings in which his defense attorneys and those of his co-defendants — aide Walt Nauta and Mar-a-Lago employee Carlos de Oliveira — will present to Judge Aileen Canon the classified information that they say could be necessary at trial, CBS News has learned.

Nauta and de Oliveira, however, are not permitted to attend Monday's sealed hearing because they lack the necessary clearances to view what could be highly sensitive government information.

The former president is charged with 40 counts, including the unlawful retention of national defense information, after prosecutors said he illegally held onto government records with classified markings after he left office. The former president and his two co-defendants are also accused of obstructing the federal probe. All have pleaded not guilty and denied wrongdoing. 

Often, criminal cases that deal with classified information require closed-door hearings under the Classified Information Procedures Act (CIPA), which gives both defense attorneys and prosecutors the opportunity to discuss in secret what sensitive evidence will be vital to making their case at trial. 

Cannon ordered attorneys for Trump and his co-defendants to be prepared to discuss their "theories" for trial and "how any classified information might be relevant or helpful to the defense." 

The special counsel's team will then have an opportunity to respond and address other sensitive issues. Prosecutors often work to limit the number of classified records they use in court cases to prevent vital government information from being made public. 

Monday's hearing comes amid ongoing and contentious court filings between Smith, Cannon and the defense over separate CIPA and non-CIPA matters, including whether the Nauta and de Oliveira should be permitted to see thousands of classified records. Their attorneys argue the defendants themselves should get access, while the Justice Department contends the evidence is too sensitive. 

Last week, Cannon ruled against Smith's team when she permitted Trump and his co-defendants to file public motions in court that might contain protected information, including witness identities and testimony. The special counsel strongly urged the judge to reconsider, citing threats to witnesses' safety. 

A media coalition that included CBS News also filed a motion seeking the release of the information.

Prosecutors wrote that any public disclosure in court filings risks publicizing "numerous potential witnesses, along with the substance of the statements they made to the FBI or the grand jury, exposing them to significant and immediate risks of threats, intimidation, and harassment, as has already happened to witnesses, law enforcement agents, judicial officers, and Department of Justice employees whose identities have been disclosed in cases in which defendant Trump is involved."

Smith's team previously disclosed that one potential witness was threatened and an investigation is underway. 

Cannon has set a May trial date for the classified documents trial and a key March hearing will decide whether the case will proceed then. Still, prosecutors have accused Trump and his co-defendants of working to delay the case, writing in court filings that they have been deploying "relentless and misleading" tactics as part of an "unceasing effort" to delay the trial. 

Robert Legare

Robert Legare is a CBS News multiplatform reporter and producer covering the Justice Department, federal courts and investigations. He was previously an associate producer for the "CBS Evening News with Norah O'Donnell."