• Trump claimed that the FBI searched his son's room during the Mar-a-Lago raid. 
  • But a former federal prosecutor dismissed Trump's claim, telling MSNBC that this seemed unlikely. 
  • Renato Mariotti said the FBI would only enter a room if they had "any reason to look for records there."

Former President Donald Trump claimed on Saturday that the FBI searched his 16-year-old son Barron's room at Mar-a-Lago last month.

In his first political rally since the August 8 raid, Trump attacked both the FBI and Justice Department, describing them as "vicious monsters" controlled by "radical left scoundrels, lawyers, and the media."

"They rifled through the first lady's closet drawers, and everything else," Trump told supporters in Wilkes-Barre, Pennsylvania.

"And even did a deep and ugly search of the room of my 16-year-old son — leaving everything they touched in far different condition than it was when they started. Can you believe it?"

A source close to Melania Trump said last month that the FBI had rifled through the former first lady's bedroom and closet at Mar-a-Lago, which "annoyed her" because she viewed it as a breach of privacy. 

"She's private, and she's protective of her son and her home," an unnamed source told CNN. There have been no reports about the FBI searching Barron's room. 

But Renato Mariotti, a former federal prosecutor, questioned Trump's claim, telling MSNBC on Sunday that FBI agents would only look for documents in Barron's room if they had "any reason to look for records there."

"In other words, if Trump is storing boxes of classified documents or presidential records or other types of documents that could potentially be one or the other in the bedroom of Barron Trump then he should understand that that's why the Justice Department is searching there," Mariotti told MSNBC. Raw Story published a clip of Mariotti's interview.

"Let's face it, I don't take anything that Trump says at face value," he added. 

During the raid, the FBI seized about 20 boxes worth of material from Trump's residence, including 11 sets marked as classified. According to The Washington Post, FBI agents seized some documents from the former president's bedroom, office, and a storage room.

The search was part of an investigation into whether Trump violated three federal laws, including the Espionage Act.

A former counterintelligence chief at the DOJ said last week that the investigation appeared to be moving toward criminal charges for Trump.

The former president was in Pennsylvania to campaign for Republicans Dr. Mehmet Oz and Doug Mastriano before the November midterm elections. 

Representatives for Trump did not immediately respond to Insider's request for comment.