Neither was Biden, and had only been vice President. when he kept them in his private residence unsecured, and trump had been president and all presidents take documents with them. Do you understand what any of that means
All presidents turn over all official presidential records to the national archive before they leave office since Nixon, when the law to do so was put in place.
Working with the National archives, presidents may obtain duplicate presidential records when requested.
You are confused between presidential records and top secret classified documents created by other intelligence agencies and or the Military.
The National archives were seeking the presidential records that are theirs to store and maintain. The national archives received FINALLY a year after trump left office, only 15 cases of presidential records to store after sorting and archiving with many of other cases of presidential records not returned.
As the archive sorted these presidential records they found top secret classified documents mixed in with the presidential records....and under the law, they were REQUIRED to notify the FBI of the top secret documents.
AFTER they notified the FBI of the top secret documents is when the FBI got involved. This was in February or March of 2022. The FBI tried to get all other top secret and higher documents trump took after that point....they could care less about the national archive's presidential records....that was the national archive's sole concern.
Trump had his lawyers commit perjury by signing an affidavit saying ALL classified documents had all been returned. A whistle blower at Mara Lago, with review of video subpoenaed showed Trump and lawyers lied and had many other top secret documents not returned....and he obstructed justice by trying to hide them.
That is when the search and seizure was obtained by the FBI through a Judge.