assassination plot against Saudi ambassador

Saudi media are relishing broadcasting the Justice Department's press conference regarding the plot against the Saudi ambassador in the US.   I don't know the details of the case: Iranian regime and Saudi regime are bitter enemies and Iran hides its hatred better than Saudi Arabia, and Iran is capable of plots of assassinations but I am very skeptical about this claim.  US media should dig deeper on this one: something is very very fishy about it.  IT does not strike me as plausible.  If the Iranian regime wants to kill a Saudi ambassador, do you know how easy it would be to do it in the Middle East?  Iranian agents have so many different countries where it would be so much easier to kill a Saudi ambassador.  This smells a rat: a scheme by a government (Saudi or US or both) to trigger some confrontation or military action.  I know Obama is desperate to win re-election but still.