Strangeways was returned for Yorkshire with his brother-in-law, the other 'knight of the shire', Sir Thomas Montford. Reappointed as a JP of the North Riding, he rode with the Yorkist nobles into southern Yorkshire to arrest and imprison the Lancastrian knights there. Strangeways made extensive use of an arbitrary piece of law "Scandalum magnatum" widely abused by the Yorkist regime. It enabled the arrest for just cause for uttering alleged falsehoods, and artisans who breached patent laws in manufacture. Its application was generalised by court officials. When Somerset's army defeated and killed the duke of York at Wakefield at the end of the year the earl of March was not present. It is likely Strangeways was captured but released by Edward when he was reported as killed at the Towton on 10 May 1461. He was immediately reinstated as JP for West Riding with his son as JP for North Riding. He was charged by the charismatic soldier-king to find and imprison leading Lancastrian rebels. Dr John Morton and Sir John Conyers were leading members of Henry VI's affinity. Morton was a former Chancellor of the Duchy of Lancaster and a senior court official. Conyers’ wife was a co-heiress to the Darcy fortune into which Strangeways had married. This was taxation by stealth, later known as Morton's Fork, one of Edward's cunning dynastic devices. The Commission of Oyer et Terminer was a State Trial that aimed at the truth about bringing lawless opponents of the regime to book through summary procedures. King Edward thanked his faithful retainer after his great victories of 1461 when the Yorkist army marched into London to announce a new reign. Edward was generous to his friends, but wrathful to those who were disloyal.