32 • So the soldiers came and broke the legs
of the first, and of the other who had been crucified with him.
33 • But when they came to Jesus
and saw that he was already dead,
they did not break his legs.
34 • But one of the soldiers pierced his side with a spear,
and at once there came out blood and water.
If the Jewish authorities had had as it were to fill in a form to get the crucifixions brought to an abrupt end, it was the soldiers who had to sign the death certificate. The preparations to bring about the end of the executions were made to protect the Sabbath day but the authentication of death was made with the view to the preservation of life. If one of these prisoners lived, then the soldiers' own lives would be forfeit so we can imagine how meticulous they were to make sure that this crucifixion really was finished.
Elsewhere in the Empire, crucifixions would last for days as the deterrent value of a long slow lingering death was brought home to all who witnessed it but here the most important thing was to get the chief prisoner dead and buried so everything would be neatly and tidily cleared up and by the next day there would be no evidence that any of these men had ever lived. The neat and tidy finish was ruled out by the inconvenient fact that one of the prisoners was already dead.
The purpose of breaking the legs was to induce swift asphyxiation as the arms would very quickly fail to pull the body up by themselves. To take the man on the centre cross down was to risk his reviving but there was no point in breaking the legs of one already dead. It must be proved that he was dead in spite of their previous precautions to keep the prisoners dying for as long as possible.
Very few doctors see traumatic death as frequently as soldiers in the Roman army did. These soldiers knew very well that dead bodies don't bleed so a spear was thrust into the side of Jesus with no expectation of any sign of life. An unnecessary coup de grâce, it might seem, but the continued life of the soldier was dependant on Jesus being dead. The stream of 'blood and water' that issued out of the wound showed that major disruption of the internal organs had taken place and that fluids had already pooled and separated within the cavities. This body was that of a man who had been dead for some time.