One of them is the relevant passage on the duties of the coroner from what was the main guide for coroners, known as Jervis on Coroners.
The duties of coroners were regulated by the Coroners Act of 1887, as modified by subsequent legislation (the most recent amendments before the Pace case had been in 1926, which had necessitated a new edition of Jervis the following year).
‘Where a coroner is informed that the dead body of a person is lying within his jurisdiction, and there is reasonable cause to suspect that such person has died either a violent or an unnatural death, or has died a sudden death of which the cause is unknown, or that such person has died in prison, or in such place or under such circumstances as to require an inquest in pursuance of any Act, the coroner, whether the cause of death arose within his jurisdiction or not, shall, as soon practicable issue his warrant for summoning not less than seven nor more than eleven good and lawful men to appear before him at a specified time and place, there to inquire as jurors touching the death of such person as aforesaid.’
-- F. Danford Thomas, M.A. Sir John Jervis on the Office and Duties of Coroners with Forms and Precedents (Seventh Edition, London: Sweet and Maxwell, 1927), pp. 20-21There were, in the event, nine jurors on the inquest jury.
To accompany this passage: a photo of the coroner who would handle the Pace inquest, Maurice Carter. (This is the only picture of him that I managed to find.)
Sunday Dispatch, 8 July 1928
Some aspects of the way that he handled the case became very controversial indeed.
At this point in our timeline, however, he was still waiting for a forensic report.