It began when Craig Anderson, 24, and his fiancee Jackie Fisher, 22, were confronted by a gunman as they sat in their parked car near Crosswood reservoir, on the main A70 Edinburgh to Lanark road.
It appeared Mr Anderson fell dying with gunshot wounds, and the Ford Capri sped off with the gunman and Ms Fisher inside. She was dumped about five miles away at Whitburn, west Lothian, where she flagged down a police patrol car.
It and another police car carrying four armed officers gave chase. The officers lost the Capri and stopped to confer when a gunman appeared. He opened fire and three officers were hit. The armed police fired back, and the man fell injured.
The three injured officers were said not to be hurt seriously.