A house is foreclosed. The new owners move in. They find something that seems odd. They call the cops. After a bit a Hazmat squad comes and removes a sample. It proves to be ricin, a killer substance used, inter alia, by the KGB to kill dissidents. So what do the feds say? No reason to suspect terrorism.
Maybe the house was previously used to film The Sopranos or 24?
Why can’t the FBI just say “we don’t know”? Jeez.