In the late 1990s, Catholics made up roughly 40 per cent of the population of Northern Ireland, but fewer than 10 per cent of RUC members. The rubber bullets that US police officers have been firing so freely were initially designed for use by the British security forces in Northern Ireland, where they killed 17 people. RUC patrols carried weapons, wore flak jackets and drove around in armour-plated vehicles, foreshadowing the militarisation of US policing.