NFA collector suing Baltimore Police
Story here. They raided him based on a tip from BATF.
Clue to local authorities: when a Federal agency has jurisdiction, and it's a big case that will draw publicity but they hand it to you .... that's right up there with an email from a guy who says he's a Nigerian bank president, has embezzled $10 million, and would like to wire it to you. They have a grudge against the guy, but know they have no case.