A former Blackwater security guard has been sentenced to life in prison and three others to 30 year jail terms over the killing of 14 Iraqi civilians in 2007. <br /><br /> In addition to the killings 17 others were injured. <br /><br /> The sentencing closes a case which had outraged Iraqis and inflamed anti-US sentiment around the world.<br /><br /> The shootings also sparked a debate over the role of defence contractors in warfare.<br /><br /> Nick Slatten (31) from Tennessee was convicted last year of murder for killing the driver of a car, the defendants had argued at trial they believed contained a bomb.<br /><br /> Paul Slough (35), from Texas, Evan Liberty (32)from New Hampshire and Dustin Heard (33) also from Tennessee were all convicted of multiple counts of manslaughter and attempted manslaughter.<br /><br /> In their statements afterwards, all four former guards maintained their innocence. and their lawyers said they would be launching appeals. <br /><br /> On September 16, 2007 the four guards had opened fire with machine guns and grenade la
