“Sandra Mitchell, a thirty-year-old homemaker. Her husband, Jim, is flying the plane. They were en route from Phoenix to Las Vegas.”

The camera moved jerkily so that the back of the pilot’s head was in frame. “Dad, Dad!” The pilot turned and gave the boy a thumbs-up.

“They were flying at about three thousand five hundred feet here, there’s a map in the file which will show you their exact position. The local police are conducting a search of the area now, but it’s going to take several days.”

The camcorder panned across the cockpit windows giving them a view of the desert far below. Sandra’s voice called out above the noise of the engine: “Don’t use all the tape.” There was a flicker showing that the video had been turned off and then there were two adults in the frame, the man and the woman standing proudly in front of their plane. It was a small Cessna, with one propeller. The man was holding in his stomach and his young wife patted him as if telling him there was no need.

The picture flickered and then there was another view out of the window. There was no way of knowing how long it had been switched off. A sandstone butte filled the screen. There was a figure lying on the top, with what looked like a rifle in his hands. The camcorder wavered as the lens zoomed in and focused on a close-up. Then the camera angled down and far below amid the cacti and brush Howard could see some sort of a tower which had been built of metal scaffolding and wooden planks.

“At about two o’clock in the afternoon they saw this structure, and another just like it, and went down to take a closer look.”

The picture swung from side to side as the boy struggled to keep the structure in sight. There was a man on the top and Howard saw that he was holding a rifle. The plane levelled off again and in the distance Howard could make out a group of figures.

The little boy played with the focus control, zooming the lens in and out on the figures standing below in the desert. It wasn’t a pleasant effect and Howard averted his eyes for a moment.

There was a sudden cracking sound and then the woman began screaming. The camcorder swung round and Howard could see there was blood all over the front of the cockpit. The top of the pilot’s head had been blown away. “My God,” whispered Howard.

The boy began screaming and the picture lurched as if the camcorder had been thrown to the side and all Howard could see was the blood-spattered material of the seat cover.

“Mrs Mitchell also had a private pilot’s licence and she took over the controls. Within thirty seconds after the first shot, eight more hit the plane.”

Howard heard the small explosions as the bullets struck home, then he heard the engine splutter and cough.