“…..Lord Phillips and Lord Judge say that a basis on which the jury's verdict can be upheld is that they must have found that the respondent aided and abetted Bandana Man to shoot at him with intent to kill or cause really serious harm. At para 59 they draw an analogy with a duel and a prize fight. If the jury's view of the facts was that this case was indeed analogous to a duel (ie that the respondent and Bandana Man had a common purpose to shoot and be shot at), then I agree with the reasoning of Lord Phillips and Lord Judge. It is important to distinguish between a combat which is analogous to a duel and a mere fight. An essential element of the former is an agreement by the combatants to fight each other. They encourage each other to fight. The judge was right to distinguish between encouragement and provocation. If A shoots back at B because he has been provoked by B's shooting to do so, that is very different from saying that A shoots back at B because he has been encouraged to do so pursuant to an agreement to have a shoot out.”
“Where there are two opposing sides to a violent conflict, all those who share the same common purpose to use unlawful violence against each other may be criminally liable for injuries caused by the mutual, unlawful violence in which they intentionally participate. Historical examples might include a duel or a prize fight. Similarly, if an individual shares a common purpose with others to engage in the joint activity of shooting at each other, or intentionally assists or intentionally encourages others during a gun battle to fire shots at each other, intending that others in the line of fire (whoever they may be) should die or suffer really serious injury, he or she will be guilty of the murder of those who die. This is irrespective of whether the victim happens to be someone "on the other side", or someone "on his side" or an innocent passer-by. In this case, before you could convict, the Prosecution must make you sure that there was a shared common purpose to shoot and be shot at.”
“….we take the view that the necessary agreement to shoot and be shot at may properly be inferred where two or more persons engage in, or assist or encourage, shooting at each other, each knowing that it was a virtual certainty that the other(s) would be armed and would either open or return fire, and each intending to kill or to cause really serious injury. It may or may not be helpful to refer to such a situation as a "shoot out": at best, that may be a convenient but imprecise shorthand description of a situation which will have to be analysed with care by a jury before the necessary agreement to shoot and be shot at can be inferred. It may be thought that the term implies the reciprocity which is a feature of the agreement which must be proved. But be that as it may, the whole purpose of each party shooting in such a situation is to kill or to cause serious injury, and it can be no defence for one party to say that the victim of the shooting was a member of his own side…. ”
“The evidence of what happened before and at the scene established a prima facie case that they both [i.e. Riley and Robinson] had participated in the planning and execution of a consensual knife fight.”