From "Anti-Zimmerman" thread:
In America I believe District Attorney's etc are directly elected officials (Law and Order often had the politics of this and elections interfering factoring into case decisions; as I believe Veldan seems concerned about here). In the UK its the role of the Crown Prosecution Service (CPS) so the people involved are non-political civil servants though Parliament can change the paramaters they operate under.
Which do you prefer? I wish we had more things directly elected like in the US (including the Police Commissioners) but for issues of the actual trials so prosecutors and judges themselves I'm uncomfortable with the notion of those roles essentially being filled by politicians looking to get elected rather than do the right thing.