I'm not sure I agree that something smells. Beyond the too-common violations of natural rights, anyway.
The Fedcoats did obtain warrants. Not that that means much; apparently you can often get a warrant on the flimsiest justification, and even screw up the information in the affidavit (the part where the Fourth Amendment talks about "...supported by oath or affirmation..."). But, at least there is reported an long-term investigation and a warrant.
At the moment, the thing that jumped out at me was the story comment that no confirmation of his being an FFL has been forthcoming. Why is the press waiting around for it. Back in the day, the press went after information; they didn't sit around waiting for it.