Ross and Norris both became sports journalists in 1950. In 1951, they published Get to Your Marks, and earlier that year they had founded an agency to provide facts and figures to Fleet Street, setting out, in Norris McWhirter's words "to supply facts and figures to newspapers, yearbooks, encyclopaedias and advertisers". While building up their business, they both worked as sports journalists. One of the athletes they knew and covered was runner Christopher Chataway, an employee at Guinness who recommended them to Hugh Beaver. After an interview in 1954 in which the Guinness directors enjoyed testing the twins' knowledge of records and unusual facts, the brothers agreed to start work on the book that would become The Guinness Book of Records. In August 1955, the first slim green volume – 198 pages long – was at the bookstalls, and in four more months it was the UK's number one non-fiction best-seller. Both brothers were regulars on the BBC show Record Breakers. They were noted for their encyclopedic memories, enabling them to provide detailed answers to questions from the audience about entries in The Guinness Book of Records. Norris continued to appear on the programme after Ross's death. In 1958, long after the legend of William Webb Ellis as the originator of rugby had become engrained in rugby culture, Ross managed to rediscover his grave in le cimetière du vieux château at Menton in Alpes Maritimes.
McWhirter advocated various restrictions on the freedom of the Irish community in Britain, such as making it compulsory for all of them to register with the local police and to provide signed photographs of themselves when renting flats or booking into hotels and hostels. In addition, McWhirter offered a £50,000 reward for information leading to a conviction for several recent high-profile bombings in England that were publicly claimed by the Provisional Irish Republican Army. In doing so, McWhirter recognised that he could then be a target himself. This was described as a bounty by McWhirter, and considered a bounty by the IRA Army Council, a view that led directly to the events that followed, although the idea was not originally his, but that of John Gouriet.
Assassination
On 27 November 1975 at 6.45 p.m., McWhirter was shot and killed by two IRA volunteers, Harry Duggan and Hugh Doherty, both of whom were members of what became known as the Balcombe Street Gang, the group for whose capture McWhirter had offered the reward. McWhirter was shot at close range in the head and chest with a.357 Magnum revolver outside his home in Village Road, Bush Hill Park. He was taken to Chase Farm Hospital, but died soon after being admitted. Duggan and Doherty were apprehended following the Balcombe Street siege and charged with murdering McWhirter, in addition to nine other victims. They were sentenced to life imprisonment, but released in 1999 under the terms of the Good Friday Agreement.
