Well, there isn&#x27;t really a single legal system in the UK.<p>Here in Scotland, which I think is fairly similar to England even though the terminology is completely different, the public prosecutor is the <i>procurator fiscal</i> who directly employs solicitors to prosecute cases in the lower courts (Sheriff Courts). Defendants will typically be defended by solicitors working criminal defence firms - often paid for by the state through Legal Aid.<p>However, for more serious crimes there is a completely separate court - the High Court of the Justiciary before which normal solicitors can&#x27;t appear - you need to be a specialised advocate and they can&#x27;t be employed directly by clients but only by solicitors (you do get Solicitor Advocates but apparently they don&#x27;t appear nearly as often as you might expect). You might be getting the idea of a shared pool from this idea of an advocate (barrister in England) who in theory will take any side of any case. In practice there are advocates working for the public prosecutor for a stint and others who focus on criminal defence. However I suspect most advocates have no desire to do criminal work unless they want to be Sheriffs or Judges.