His name does not appear in the official list of returns to parliament after 1597. He was certainly, however, the member for
Saltash in 1614, and was elected
speaker (7 April). He was knighted in June, and took the degree of
serjeant-at-law in July of the following year. In the address with which, according to custom, he opened the session in 1614, he enlarged upon the length of the royal pedigree, to which he gave a fabulous extension. In January 1614–15, Crewe was appointed one of the commissioners for the examination, under
torture, of the
Puritan minister
Edmond Peacham for
high treason, in that his attacks, which were never published, on the King and his ministers could be construed as incitement to
regicide and
rebellion. Peacham refused to speak even after being tortured on the
rack. Crewe concurred with the advice of the majority of the High Court judges that Peacham's unpublished writings clearly amounted to treason, although Coke in a celebrated ruling called ''Peacham's Case'' vehemently disagreed. Peacham was sent down to
Somersetshire to stand his trial at the
assizes. Crewe prosecuted, and Peacham was convicted. He was sentenced to death but allowed to die in prison. Crewe's professional reputation was somewhat damaged by the
Leicester boy Witch Trials, where he sat as an extra judge of assize. Nine women were hanged on the evidence of a young boy called John Smith whom Crewe, and his colleague Sir
Humphrey Winch, found entirely credible, but whom
King James soon after declared to be a fraud. Crewe was a member of the commission which tried Richard Weston for the murder of Sir
Thomas Overbury in 1615, and was concerned with
Bacon and Montague in the prosecution of the
Earl and
Countess of Somerset as accessories before the fact to Overbury's murder in the following year. In 1621 he conducted the prosecution of
Henry Yelverton, the
attorney-general, for certain alleged misdemeanours in connection with patents. The same year Crewe prosecuted Sir
Francis Mitchell for alleged corrupt practices in executing 'the commission concerning gold and silver thread,' conducted the impeachment of
Sir John Bennet, judge of the
Prerogative court, for corruption in his office, and materially contributed to the settlement of an important point in the law of impeachment. Edward Floyde, having published a libel on the
Princess Palatine, was impeached by the
commons, and sentenced to the pillory. The
lords disputed the right of the
commons to pass sentence upon the offender on two grounds : (1) that he was not a member of their house; (2) that the offence did not touch their privileges. At the conference which followed Crewe adduced a precedent from the reign of
Henry IV in support of the contention of the
lords, and the
commons being able to produce no counter-precedent the question was quietly settled by the
commons entering in the journal a minute to the effect that the proceedings against Floyde should not become a precedent. In 1624 Crewe presented part of the case against
Lionel Cranfield, earl of Middlesex, on his impeachment. The same year he was appointed
king's serjeant. ==Lord Chief Justice==