‘It’s my job to film sport,’ the cameraman said. ‘I don’t want any part of whatever this is.’

His voice was thin and nervous, but he stood his ground. Saunders snapped. He leaned forward and grabbed the camera and smashed it hard into the cameraman’s face. The cameraman dropped to his knees, holding his face in his hands. The whole thing took two seconds.

But two seconds was all Chris Foster needed.

He saw his chance and exploded across the court towards Saunders. By the time the umpire realised what was happening, Foster had covered half of the ground between them and was still accelerating. Keller could see him coming, and as Saunders grabbed for her again, she used all the strength she had left to smash into her tormentor for the second time that afternoon, knocking the wind out of him and causing him to topple backwards.

Police marksmen, who had been slowly edging along the gantries high above, began calling sharp instructions to each other as the situation below them suddenly changed. Saunders ignored them, his mind fixed on finishing the job. He scrambled from underneath Keller and punched her hard in the ribs, pulling her up by her hair and dragging her up the flight of concrete stairs. It was hopeless; Foster was almost on him. As Saunders reached the top of the stairs he could almost feel Foster’s breath, so he took the only option he had left. He pushed the tip of the knife into Kirsten Keller’s throat. It cut deep enough to draw blood, a gentle river pooling on the blade and then dripping slowly down onto her whites.

Foster froze, as he knew he had to, and Saunders pulled Keller through into the players’ box. But Foster was aware of the net tightening around all of them, with the police teams repositioning and drawing slowly closer.

‘You know the problem with all of this?’ he told Saunders. ‘My guess is that your brother loved her. Loved the bones of her. Loved her enough to kill himself. This is not what he would want.’

Saunders looked for a moment as if he had seen reason, and he slowly straightened up, lowered the knife and eased Keller away from him. Foster sprinted into the players’ box to grab her, but at the last second Saunders shoved her hard in the back and she toppled sideways over the edge of the balcony with the noose around her neck.