Margaret was quite unruffled. “This victim died from a separation of the skull from the first vertebra of the neck. It’s known as an Atlanto-occipital disarticulation. The first vertebra, the one on which the head rests, is called the atlas.” She smiled sweetly. “Those anatomists were cute with names, don’t you think?” This failed to raise a smile. She shrugged. “Anyway, it is jointed in two places to the occipital bone at the base of the skull. When the separation of one from the other occurs, probably with a double ‘pop,’ much like the cracking of your knuckles, the spinal column is severed by the edge of the foramen magnum through which it passes into the skull. Death would have been instantaneous, a very rare thing. Most deaths—including our previous autopsy, the single knife strike to the heart—take a minute or two.” She removed the goggles which she had pushed high up on her head and pulled and stretched the elastic as she spoke. “This particular injury is very common in automobile accidents, but a lack of any other major trauma in this case means he probably wasn’t in a car at the time.”

Again she smiled, and again found that no one else shared her sense of humour. She sighed. “From the absence of any finger bruising on the victim’s neck or face, I would suggest that his assailant grasped the victim with the arms, one around the forehead, the other at the base of the back of the head, twisting while forcing upwards and forwards, causing the foramen magnum to slide across the top of the spinal column and sever the spinal cord. Such a clean and fatal break, in the absence of other major trauma, suggests to me a substantial degree of expertise.”

The imagery conjured up by Margaret’s description left everyone in the room uneasy.

“In our previous autopsy . . .” She checked her watch. “Goodness, how time flies when you’re enjoying yourself.” The faces around the room stared back at her with a serious intensity. Didn’t they realise, she wondered, that humour was the only thing that kept you sane in this job? “In our previous autopsy, the victim was killed by a single stab wound to the heart. My guess would be that he was approached from the rear, held around the neck by an arm, and the knife driven inwards and upwards by the assailant with his free hand. The blade was about nine inches long. It entered at the base of the breastbone, severing parts of both the left and right ventricles. The direction from which the stab came is unreliable. So I can’t tell you if the killer was left- or right-handed. That’s just for the movies. But I can tell you that the delivery of a single, fatal wound of this nature would require considerable skill.”