Why would a forger be so precise?
The four circle blood marks on the back of the man of the Shroud

When looking into the details of the images on the Shroud, we are constantly surprised by the precision of reality it describes. The photograph presented below is yet another example. If a forger, from the fourteen century, ever thought about producing the details we are going to study, he or she went well beyond what any artist would ever do during the next five centuries. These details alone are enough to convince most people that the Shroud is not a painting. They are way too small and too subtle for a painter to do by hand. It goes well beyond the necessity of forgery.

What am I referring to?

The photograph below is a close up in the region of the butts of the man of the Shroud. We can see numerous whip marks in red/brown color. These are to be expected. What is unexpected are the four circles of blood, two on each side. The vertical distance between the center of the circles on the left is about six and half centimeters. For verifying such measurements and see the context of this photograph, try the Shroud Scope. We have the same distance between the right circles. On the left there is a clear dark round circle, of about one and a half centimeter in diameter, with a darker center of a few millimeters (less than 4 millimeters). The lower left circle is dimer but has a more spread out center. On the right we have a slightly different configuration. The upper right circle is about the same size as the one on the upper left with a single darker center. But the bottom right circle appears to have two darker spots with a more distinctive circle. The circles themselves can be easily explained: they are most probably the blood plasma that spread by capillarity. Blood plasma makes up 55% of blood and is the component that easily spread by capillarity since it is made mostly of water.

We can see four distinct circles of blood plasma, two on each side of this photograph. On the right side, there are three darker blood marks. The upper one has a circle of blood plasma around it. The two lower ones are close to each other, also in a circle of blood plasma. On the left, essentially the same pattern, but the two close blood marks are lighter in color. These two lighter blood marks appear in a more curved region of the body. That is, they are more on the side of the butt. This is coherent with the supposition that all these wounds are from a pair of three spikes.
Photograph kindly provided by Barrie Schwortz. Copyright Barrie Schwortz.

But what created these distinctive wounds?

Historically, it was mentioned that sometimes a sedillis was nailed on the cross at the level of the butts to either help the crucified rest on it or to increase pain and humiliation. Indeed, Seneca described the sedillis as "acuta sedere cruce", which refers to a "cutting edge". It appears that this sedillis would cause further wounds at the level of the butts. From historical writing it appears that there were several versions of that sedillis, and that the Shroud reveals something very peculiar about the sedillis on which the man of the Shroud was subjected to.

The Shroud shows two sets of three nails or spikes, forming a triangle, that were at the level of the butts, on the cross, such that lowering the body to reduce the pain in the arms would wound the crucified in the butts.

Moreover, notice from the more general context of the complete photograph (see photograph of Enrie on Shroud Scope centered on the butts) that the lower left circle appears more on the side of the body than the right side. It means that the tip of the outside spike on the left is further away from the body due to the curvature of the butt. That would explain the less pronounced wound for this particular spike. If a forger thought about such details, he or she expected way too much knowledge from the credulous. The likely conclusion is that it was not made by a forger and that this Shroud comes from a real man that was crucified on a Roman cross.

Note: It was pointed out to me by Yannick Clément that these marks could be burned marks and not bloodstains based on the study of Miller and Pellicori. Although, not impossible, this argument would be based on the burned marks being produced while the Shroud was folded. An analysis of the marks on the reverse side (photographs of 2002, published by Ghiberti) shows that this is unlikely, as the color intensities of the marks on the backside do not match a transmission of the burning material from front to back and from back to front again. Furthermore, the work of Miller and Pellicori suggests that the stains resemble scorch marks as their imaging techniques cannot definitely differenciate between scorch marks and bloodstains.