Expert Witnesses

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At this stage we are not going into conduct issues. We are going to look at some very basic findings of some experts, notably those of Mr Pat Wertheim and Mr Arie Zeelenberg, who both vehemently upheld and nurtured the flawed drinking glass theory. However, there seems to have been many contradictions between these two experts.

In August 2005 Mr Daan Bekker was the first expert who was asked by the defence to write a report on Folien 1. In a very old school and uninspiring report which largely rested on visual observation alone, it is notable that he does not say one word about the “lip print“.

Mr Pat Wertheim, an expert from Tucson, Arizona, USA, was asked in August 2006 to compile a report. The accused’s father was present when Mr Wertheim conducted the experiments for this report. Wertheim was instrumental in establishing the glass theory as “fact”, and was also the expert who vehemently went on after the cases were finished in defence of the drinking glass theory, relentlessly accusing the police of evidence fabrication.

Superintendent Roger Dixon, a geologist from the SAPS Forensic Centre in Pretoria, did experiments with “glasses collected from 21 Shiraz” in December 2006. His finding was that Folien 1 was lifted from 1 of 4 short glasses that apparently came from Inge’s flat.

Mr Arie Zeelenberg, from The Netherlands, and a good acquaintance of Mr Wertheim, was retained as a defence expert during the criminal trial.

We’re not going into great lengths here at this very moment, and we’ll leave Daan Bekker’s report aside for now. We just want to look at some basic but flawed premises that were established.

Breaking the chronology a bit, we’ll briefly look at one or two aspects of Dixon’s report first. We must remember the significance of Dixon’s report. When he, as a member of the SAPS who was appointed by the State to investigate Folien 1, found that Folien 1 was lifted from a glass in Inge’s flat, the State started to doubt whether Folien 1 was indeed lifted from a DVD case. Maybe a mistake was made, they probably thought. So much so that they withdrew the fingerprint evidence. It was a massive blow to the State’s case even before the trial started in early 2007.

Eleven glasses that were not taken in as evidence and were not in sealed evidence bags, were used in experiments by Dixon on 5 December 2006, a year and nine months after the murder. Thus, we do not know if they were the actual glasses “collected” from 21 Shiraz. There was no proper chain of custody. They could have been planted or they could have been switched. Be that as it may, if we assume for now they were indeed the glasses that were in Inge’s flat, the following is interesting: Dixon writes in his report that 4 glasses were found to have the “same height” as the distance between the lines on Folien 1 – which is 80 mm.


However, this glass (as one of the 4 glass-set) is clearly 83 mm high and not 80 mm!

Dixon also says that the curves this glass produced were “consistent” with the “parallel curved lines” on Folien 1. Apart from omitting to tell us on what basis he determined that the lines of Folien 1 are indeed both “curved and parallel”, we did a scientific calculation and simulation of the curves that this glass would have produced (based on the top and bottom diameters, and height) and found that it would be impossible for this glass to leave curves that fitted the lines on Folien 1.


The top illustration shows that the curves that this Glass 1 (or any of the other three of the set) would have made, do not fit the lines of Folien 1.


Not one of the experts, including Dixon, had any basis to say that the lines were “curved and parallel”. Unless it was intentional omission, this “fact” was based on visual observation and assumption alone. As we also see below, the lines are also not parallel as they should have been had they been from a drinking glass.


All pink lines are equal in length and hang from the inner edge of the top line. Clearly showing that the lines are not parallel.


Pat Wertheim and his co-defence expert, Arie Zeelenberg, had some conflicting views. This is despite the fact that Wertheim claims that Zeelenberg peer reviewed his report. As it was never revealed, we do not know who reviewed Zeelenberg’s report.

Wertheim and Zeelenberg could hardly agree on one aspect of the “lip print”. Wertheim said the lip print is parallel to the rim of the glass. Zeelenberg said it is sloped and that it should be sloped. Lip prints are normally sloped, he said. Wertheim said it was an “excessively wet” lip put on a dry glass. Zeelenberg said it was a dry lip put on a condensed glass. Wertheim said it is OK for the lip print to sit to the left of the right thumb. Zeelenberg claimed “another thumb print” print without any perceived methodology to be a right thumb; so that he could place the lip to the right of this new print.

Wertheim says, based on visual observation alone, that the left index finger is curved, foreshortened and rolled onto a side. Zeelenberg implies on some of his slides that the finger is not foreshortened.

Zeelenberg says that the absence of creases in the lip print is due to the fact that the lip was put on a fully condensed drinking glass. The whole glass up to the rim thus had to be full of condensation. That is what he wants us to believe. Then a skewed lip was put onto it.

But please take note, condensation is all over a glass and not only on certain parts. However, it will not significantly go above the water line. The cold water in essence plays a role in the formation of condensation as the colder temperature of the water on the inside reacts through the glass with the warmer air on the other side, which forms the droplets.

Was the glass filled up to the brim? If so, imagine for one moment if you then drink in such a way that you leave a sloped lip of 10 degrees. Imagine the spillage! There is no evidence on Folien 1 that there was spillage or damp or condensation on the surface it was lifted from.

Just as one example, let us look at one of Zeelenberg’s arguments. What did Zeelenberg do to prove his condensation theory? Quite classic Zeelenberg, he simply decides the lip was as a fact put on condensation. Then he puts a DVD cover in a fridge. When he takes it out and cannot find any condensation on it, he offers it as proof that the lip was put on glass and not on a DVD cover, as the lip had to be put on something that can condense. He uses this argument to exclude the DVD cover.

This also, of course, without showing us any lip prints on condensed drinking glasses, or to consider the wet latex on plastic claim.

As mentioned, we’ll keep it short for now, and for now we will limit it to this. However, this page will be updated fully in due course. We can write pages about their reports.

For now, go through their reports and decide for yourself. Highlights include Wertheim’s results of his paragraph 55 experiment and Zeelenberg’s explanation of why lip prints will normally be sloped. And so on.

Here are their reports, which formed the basis of their testimonies and campaigns.

Pat Wertheim

Arie Zeelenberg Part 1

Arie Zeelenberg Part 2

Open Letter to Roger Dixon

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