The armed suspect who tried to enter a US Federal Bureau of Investigation (FBI) office in Cincinnati, Ohio, and was shot dead after a shootout with law enforcement officers was a US Navy and Florida National Guard veteran, according to The Wall Street Journal reports.

The suspect was identified as Ricky Walter Shiffer Jr., 42, who served in 1998-2003 aboard the USS Columbia and in 2008-2011 as an infantryman in the Florida National Guard, WSJ said on Friday citing the Shiffer's personnel records.

The Washington Post said Shiffer oversaw equipment linked to weapons like missiles and torpedoes on the USS Columbia, which required one of the highest security clearances.

US media reports revealed that the suspect's posts on social media indicate he backed US President Donald Trump. The Post said his attempted attack is possibly a response to the raid of Trump’s Mar-a-Lago residence in Florida.

Yesterday, the FBI recovered 11 sets of classified documents, according to the WSJ, including some labeled as "Top Secret".  

In addition, about 20 boxes of materials were retrieved from Trump's residence, including handwritten notes, executive orders, and other documents, according to the report. 

After the FBI raided Trump's Mar-A-Lago residence in Florida on August 8, Trump accused his political enemies of weaponizing the judicial system against him. 

The raid sparked outrage among Republicans, and former US President Donald Trump complained that he had been barred from re-entering his Florida resort home, suggesting that FBI agents might be "planting" evidence there.

The Federal Bureau of Investigation has refused to provide details about the raid at the palatial West Palm Beach residence, a stunning escalation of the multiple legal investigations into the 45th President.