New Zealand police said Saturday an autopsy would determine whether one of their men shot dead an innocent 17-year-old father and courier in a shoot-out with a gunman who had led them on a 40 minute chase through the Auckland suburbs at up to 160 kilometres an hour. The gunman, who had fired at a police helicopter during the chase, was trying to hijack the van of Halatau Nitoko after crashing a stolen car on a city motorway on Friday. Police said it was not known whether the gunman, who had a sawn off. 22 rifle, killed Nitoko or whether the deadly shot had come frmo one of the pursuing officers.