The freeholders books were used for summoning jury panels to attend courts of assizes and quarter sessions. Two types of jury were empanelled at criminal trials: grand and petty juries. The grand jury heard the prosecution evidence in camera before deciding whether a strong enough case existed for the accused to be brought to trial.39 Where the bill of indictment was felt to deserve an answer, it was endorsed billa vera or 'true bill'. Otherwise ignoramus was written on the indictment and the accused was free to leave the court.40 Where a true bill was issued, the case against the suspect was then heard by the petty jury who would decide on a verdict.
The responsibility for returning a list of suitable trial jurors lay with the sheriff of the county.41 Under the 1730 Act the sheriff was required to summon a panel of between 48 and 72 men from whom the trial juries would be selected.42 Each jury had its own particular social character, with the grand jury at the assize consisting of the most socially exalted group of jurors. Few assize records survive for Devon during the eighteenth century, but it is likely that the composition of the grand jury was similar to other counties. In Essex grand jurors at the assizes were substantial men, many of whom were on the commission of the peace and sat on the quarter sessions bench.43 Beneath the grand jury at assizes in terms of social composition lay its equivalent at the quarter sessions. This was followed by the assize and quarter sessions petty juries respectively. There was no clearly defined qualification for serving on quarter sessions grand juries, but they were generally expected to consist of substantial inhabitants.44
The names of those empanelled and sworn to serve on grand and petty juries at the Devon quarter sessions survive in two locations. Jury panels can often be found among the bundles of sessions papers preserved in the Devon Heritage Centre.45 These provide the names, parish of residence, and usually the status of those summoned from the freeholders books to appear at a particular session. They are generally annotated to indicate which individuals had been sworn, and also those excused. Further to these, a series of volumes survive from 1730 onwards containing the names of grand jurors sworn at each session and, from 1761, the names of petty jurors together with details of the verdicts they returned in particular cases.46 A brief survey of these sources confirms that there was a marked difference in the social composition of the two types of jury. At the Michaelmas sessions, 1741, 37 of 40 men included on the grand jury panel were described as gentlemen, along with a merchant, an ironmonger and a mercer. This compares with 36 yeomen, a clothier, a taylor, a sergemaker and a maltster summoned to the petty jury. At the subsequent Christmas sessions all 39 of those summoned to the grand jury were gentlemen, compared with 37 yeomen, a sergemaker and a shopkeeper called to the petty jury.47 Judging from the descriptions of grand jurors contained in the register books from 1730 until 1800 the higher jury was virtually the exclusive preserve of gentlemen throughout the century.48 Petty juries consisted of twelve men, while the grand jury was usually made up of 20-25 individuals.