First step: The person charged appears before the magistrates' court. Committal proceedings, where the evidence in statements can be reviewed and argument whether these show a prima facie case, were abolished for all indictable offences, such as murder, in January 2001
Second step: the accused is sent immediately to the Crown Court
Third step: the preliminary hearing before a judge of the Crown Court. If the defendant enters a plea of guilty, the judge directs an indictment be prepared, the defendant is formally arraigned (asked to plead to the indictment) and is sentenced, after reports are prepared. If he indicates a plea of not guilty, the judge directs that evidence be prepared in statements to show a prima facie case and makes such other directions as may be necessary.
Manslaughter. The defendant can offer a plea of guilty to manslaughter at any stage, though the indictment is for murder only. Whether that plea is accepted depends on what basis it is offered. The prosecution might be persuaded that the evidence does not justify murder . It may be that they agree that the necessary intent ( either to kill or inflict grievous bodily harm) is not established, but it does establish manslaughter. Alternatively, the defendant may plead "diminished responsibility", a statutory defence which reduces murder to manslaughter. Diminished responsibility is a kind of temporary insanity, a loss of self-control for a brief moment, which is caused by circumstances: the usual one is extreme provocation causing the defendant to lose self-control, to be temporarily unbalanced, and kill the victim. The prosecution will examine the evidence and also any medical reports and material from the defence and decide whether to pursue the murder count. They usually decide to go on and leave the jury to decide whether diminished responsibility applies.