Former FBI director Robert Mueller’s ongoing investigation into links between the Russian government and Donald Trump’s election campaign is fascinating. At least, it would be fascinating if the average non-wonk had a decent working knowledge of the US legal system, but that isn’t the case. However, everyone watches a lot of US crime drama, So, here is a guide for dummies, with help from The Sopranos, The Wire and The Good Wife.

Proactive cooperator

If there is a fictional analog to the announcement that George Papadopoulos had been made a “proactive cooperator” by the FBI, it is “Big Pussy” Bonpensiero from The Sopranos. Like Papadopoulos, Pussy was collared by the FBI and given the choice of a harsh prison sentence or a new job as an informer. He chose the latter and was forced to wear wires and give the bureau information on Tony Soprano. However, Tony realised the scale of Pussy’s deception after dreaming about a fish and murdered him on a boat.

Rico

It has been observed that Mueller is approaching this investigation as he would a Racketeer Influenced and Corrupt Organizations Act (Rico) case, starting at the bottom and working up in an attempt to try leaders for crimes that they ordered underlings to commit. For a better understanding of this, the Sandpiper Crossing arc of Better Call Saul is incredibly helpful. Jimmy McGill gets a sniff of a case regarding overcharging at a nursing home, and quickly scales up until he discovers proof of illicit interstate commerce, which might be enough to bring down the entire organisation.

Grand jury

Only the US and Liberia still use grand juries – such as the one Mueller assembled in August – to screen criminal indictments, so you could be forgiven for not knowing where to start with them. A grand jury is a panel of roughly 20 citizens, who hear evidence presented by prosecutors and decide whether there is probable cause to charge someone with an offence. You can see a relatively convincing grand jury play out in the third series of The Good Wife, when Will Gardner was charged with judicial bribery. The Wire’s Clay Davis was the subject of a grand jury, over corruption claims, in series five, but basically charmed his way out of indictment. Fortunately for Mueller, no one in Trump’s circle is remotely charming.

Fisa

This stands for the Foreign Intelligence Surveillance Act, which the FBI reportedly used to chase down Trump’s former campaign chairman Paul Manafort. Fisa allows for the collection of intelligence information between foreign powers and agents of foreign powers suspected of espionage or terrorism. Think back to the first series of Homeland. It is only when Saul is granted a Fisa warrant that Carrie can investigate legally the apparent radicalisation of Nicholas Brody.

Special counsel

What does Mueller actually do? In this case, try not to rely on TV. Person of Interest had a character named Special Counsel, who worked for the US Office of Special Counsel. However, since he spent his life overseeing the invention of an artificial intelligence system capable of killing terrorists, then killing the inventors to keep it secret, he probably isn’t relevant here.