All of the counts on the indictment of Rebekah Brooks, Andy Coulson and six others involve the offence of conspiracy. As this is an often misunderstood term, I thought a short guide to it might be helpful to those following the case.
The crime of conspiracy occurs when two or more people agree to carry out a criminal act. The most important point is that it is the agreement, and the agreement alone, that is the crime. Even if the act itself never takes place the crime occurs as soon as the agreement is reached.
An example of this would a case where a disgruntled man hires someone to kill his wife. He recruits a potential killer, they agree a price and shake hands on the deal but the murder never happens. Perhaps the man changes his mind after five minutes and calls the whole thing off, or the potential hit man just takes the money and goes home. In terms of a conspiracy charge none of that matters the offence was complete when they shook hands.
Even the motives of the conspirators are irrelevant. In the case of in Yip Chiu-Cheung v The Queen (1994) one of those involved was an undercover police officer who was only there to catch drug dealers. That did not mean the main defendant was innocent, the guilty act ("actus reus" in the legal jargon) occurred immediately after the agreement was concluded.
One qualification should be made on this. A conspiracy must involve an action, it cannot just be a mental operation people sharing a thought. There must be evidence of spoken or written words or other overt acts which show agreement. This matters because, for example, if an employee of a newspaper found out that journalists were hacking phones but did nothing about it, they would not be guilty of any charge of conspiracy as they have not been party to any agreement. There is generally no duty on anyone to report evidence of a crime to the authorities, although it would be an offence to deny knowledge if asked by a investigating police officer directly.
Finally conspiracy charges are not always added to an indictment, in this case the alleged phone hacking, perversion of the course of justice and bribing public officials are crimes in themselves. The Crown Prosecution Service guidance on this states that conspiracy should be added to the charges only when "the substantive counts do not represent the overall criminality of the defendant's actions." When it comes to sentencing, conspiracy is an aggravating factor that the judge will take into account when setting the penalty