In February 1974 , Detective Chief Superintendent Oldfield as head of the West Yorkshire CID , took command of the investigation into an Irish Republican Army bomb which had killed 12 people on board a coach carrying members of the British armed services along the M62 motorway on 4 February ; he immediately made contact with the Garda Síochána and ordered forensic tests on the wreckage on the motorway . On 19 February the investigation charged Judith Ward with the bombing after she confessed and Griess tests on her hands indicated contact with explosives . Although she later retracted her confession , Ward was convicted of the bombing on 4 November 1974 and sentenced to 30 years ' imprisonment
killed 12 people on board a coach
M62 coach bombing
George Oldfield (police officer)