The Hammer

Warning – This page contains graphic photos of wounds and skull fractures.


During a search of his vehicle and flat on 15 April 2005, when the police asked Fred van der Vyver if he had “anything of value” in his white Corsa bakkie, he showed them the hammer which he got as a Christmas gift from Inge about four months earlier.

This particular hammer would be contested during the trial as possibly being the weapon that inflicted the head wounds and fractures.

The defence experts, relying on measurements in the autopsy report, argued that the round striking surface of the hammer was too small to have inflicted wounds 1(a) and 1(b). [Read here for proof that the sizes of these wounds were recorded incorrectly in the autopsy report and that their real dimensions are ±20 mm – about the same as the diameter of the round striking surface of the suspect hammer.]

Apparently, also, Inge’s DNA could not be detected on the hammer. [Read here why it was unlikely to find Inge’s DNA on a hammer that was cleaned well and that was handled by Fred van der Vyver with his bare hands immediately before the police took possession of it.]

During a test on a pig’s heads, the hammer bent on impact, and the defence also used this to refute the hammer as a possible murder weapon. The defence expert (Prof Gert Saayman) said the ±350 g hammer is too light and small to have caused the comminute skull fractures on the left and right sides of the skull.

However, the question remains:

(1:1 overlays applied to the right)

Let’s look at some photos:

Above: This skull fracture (on Inge’s forehead) is a well-defined depressed fracture, and is very indicative of a hammer blow. Even Prof Saayman, for the defence, conceded that a hammer could have caused this wound. It has a diameter of ±20 mm – fitting the round striking face of the suspect hammer perfectly.

Above: This photo shows a piece of the earlobe sliced. One needs to ask yourself what kind of weapon would be able to this: that will both slice the ear lobe AND make deep penetrating wound? According to the autopsy report this linear wound measures 30 mm – which corresponds with the measurement scope of the linear striking side of the suspect hammer (bevelled from ±30-37 mm). Considering defence experts Saayman and Grimm’s suggested weapons, can a pipe, torch, or hand-gun cause such a slice (plus a deep penetrating wound below it)? (To the right is a non-scaled photo of the bottle-opener side of the suspect hammer.)

It is not hard to imagine how the bottle-opener side’s blade sliced the earlobe as it deeply penetrated the skull just behind the ear, at the same time.

Above: In the comminuted fracture on the left side of the head we have two features that clearly and respectively correspond with both striking sides of the suspect hammer. Left is a punched-in hole of ±20 mm and to the right a linear tear of ±37 mm. (Photo enlarged)

Above: In the right side comminuted fracture we clearly see two linear features (in the two yellow blocks to the left) with the same length (also the same length as the linear feature in the left side comminuted fracture), giving us three linear features corresponding with the bottle opener side’s length. Plus one circular feature (hole) fitting the round striking side. We also see a fractured bone that fits the neck of the hammer very well. (Photo enlarged)

Above: This 1:1 overlay shows how the piece of fractured bone fits the neck of the hammer. [Please take note that the piece of bone in the yellow square has been rotated slightly clockwise by us. It is clear that this bone fragment broke loose from the skull and could well have moved during the blow or during the defleshing process. The idea was to show how well it fits the neck of the hammer while the shaft fits on the crack in the skull. The eventual position is evident in the photo above this image – in the yellow block to the right.]

Let us briefly look at the wounds on Inge’s hand.

Above: If we look at the wounds on the hand, which Prof. Gert Saayman did not say much (if anything) about, then we need to consider this: they are most likely defensive wounds – i.e. Inge stretched her hand (palm down) over her head to defend herself after the first blow fell. Would these have been made by two weapons, or one? Would it be easier to just flick one weapon around to inflict the wounds with both sides of something like a similar hammer, or would the killer first change weapons? The shapes are clearly indicative of the suspect hammer’s two sides. Using two weapons seem unlikely and impractical. Saayman and Grimm’s suggestions of a pipe, torch, or hand-gun fail dismally here. It is very hard to imagine how a pipe, torch, or hand-gun would cause such defined wounds. (We must keep in mind that a hammer will not always leave a full round wound, as it may depend on the impact angle.)

Above: These are the four main wounds on the right side of the head. The circular wounds were determined to be ±20 mm and the linear wounds were recorded as 30 mm and 35 mm respectively (though per scale both seem to be ±35 mm). This correlates very well with the aspect ratio range of the two sides of the hammer (accounting for the bevelled nature thereof). This means that if two weapons were used, their striking sides coincidentally had to have had a similar aspect ratio range compared to that of the suspect hammer’s two sides (reasonable margin of error granted). Or if it was any one other weapon, that that weapon’s two sides happened to have the same aspect ratio range as the suspect hammer’s two sides. This defies probability.

While the skin wounds’ exact sizes may be disputable, we have an aspect ratio between the linear fractures and a hole in the skull which correlates perfectly with the aspect ratio of the suspect hammer’s two sides. Statistically, this rules out any other object or two other objects, or at the very least makes it highly improbable.

[Aspect ratio means the relationship between two lengths. The hammer’s ratio would be 20/37 = 0.54. When you divide the length of the linear wounds into the length of the circular wounds (diameter), you also get around this ratio.]

In terms of skin wounds and skull fractures and features we have demonstrable and irrefutable evidence that both sides of the hammer can be reconciled with the headwounds.


When we wonder about the strength of the hammer and its ability to inflict significant wounds to the skin or fractures to the skull, then we need to remember that many variables are involved, and unless we do hitting tests with the actual hammer on Inge’s skull, we cannot say for sure that it would not be strong enough. Or even that it will be strong enough. We will never be able to do this experiment but we can ask ourselves some very basic and logical questions.

Considering that this object travels to your head at about 2-3 m/s, and considering your temporal skull bone (where most blows fell) is only ±4 mm thick, what do you think will happen? Take your middle finger and tap it quite hard on your temporal bone (just above your ear). Now imagine it being hit with this hammer’s head travelling at 2-3 m/s.

Regarding whether the opener end would be strong enough: Firstly, there is absolutely nothing to read into the fact that the hammer bent on a pig’s head that was resting on steel table. Nothing. The hammer is bound to be damaged one way or another, considering the extreme strength of the blows (by Captain Jannie Bester) as can be seen on the video of the tests. There are vast differences between a pig’s head held down on an immovable steel table and a human head on a soft pillow and that is able to move around and rotate freely.

When you look at both the right and left side comminuted fractures, and we for the sake of the argument consider blows by a similar hammer, then it may be possible that the linear features were inflicted after the skull has already shattered as a result of two or three hard blows with the stronger side of the hammer (even the side of the hammer) concentrated over a relatively small area. So when the blows with the opener side fell, the skull was already severely weakened – therefore, one would expect the opener side to have experienced significantly reduced strain.

[Pertaining to the animated image above, we do not suggest any particular order of blows, but simply wanted to illustrate that some earlier blows may have weakened the skull by the time later blows fell, making it easier for the hammer to handle the blows – reducing the chance of damage to it. Also that the collective effect of the blows led to the larger fracture.]

Defence experts Saayman and Grimm severely contradicted each other regarding the ability of the hammer and neither of them did one single experiment or showed any comparative data to substantiate their respective claims.

All in all, there is no proven reason to exclude the suspect hammer as the potential murder weapon based on its size and strength.


Let us look at some marks on the towel, and what this tells us about the possibility of a similar hammer being the murder weapon.