 The two policemen were also unaware that a British Army surveillance team had watched and noted IRA "dickers" following Buchanan's car but had failed to warn RUC Special Branch of this.Prompt notification by the British Army or MI5 would have precluded Breen and Buchanan from crossing the border on 20 March 1989 in a targeted car.Shortly before coming upon the scene of the killings, a civilian witness had observed British Army helicopters patrolling over the area.