Read the indictments; he's CHARGED with four federal felonies related to 1/6 and thirty-seven related to mishandling classified materials. As with everyone prior who's been under suspicion backed by enough evidence to justify bringing CHARGES, he's been arrested, indicted per the 5th Amendment's provision that "no person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury," released on personal recognizance with no cash bond.
Additonally, per the Fouth Amendment's provision that "no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized" his various properties have been accordingly searched, items seized as justified by probable cause generated by his own actions, supported by oaths or affirmations of witnesses. Although unlike many others indicted on federal charges, he's still walking free pending trial so far -despite doing his obvious damnedest to taint/prejudice the jury pool with accusations of bias, racism, discrimination, persecution.
What crimes has Trump committed? That's up to the jury to decide as provided under the Sixth Amendment. Quite frankly, if you think he's been treated unfairly, you're right --and you should hope to be treated with such unfair coddling as Trump by the judicial system if ever you find yourself under federal indictment.