Court resumed on 07 November 2016 @ 10:15.
This is the last witness for the defence, after which final arguments will be made on 22 November by the State, represented by Christhénus van der Vijver, and by William Booth who is representing murder-accused Zwelethu Mthethwa.
The following dialogue has been taken from the official court transcript. The dialogue has however been restructured slightly to provide a more coherent read.
The witness, Petronella van der Westhuizen, is called and sworn in. The owner of Crime Scene Solutions will be assisting the court in the matter of DNA evidence. Interestingly, van der Westhuizen was only approached by Booth on the afternoon of October 18th 2016, less than a month before this appearance in the Western Cape High Court.
Photos of the scene, the post-mortem, the vehicle, and CCTV footage have been provided to van der Westhuizen in preparation of her report. The question that was posed to van der Westhuizen by the defence was whether it would be possible for a secondary transfer of DNA to have taken place (in regards to the ‘driver’), and in fact what possibilities there were of any source of DNA transfer from an assailant to a vehicle after an assault as per the CCTV footage (if the ‘driver’ was indeed the assailant).
van der Westhuizen: A secondary transfer M’Lady is when there is no primary contact with, or in other words direct contact between the victim and the assailant but indirect transfer. So it means that it could be done in two ways, a person would for example assault someone and would have blood or something on his hands and he would transfer it to another object that wasn’t involved in the actual assault, or it could also mean that an assault could have taken place, someone else come onto the scene and gets blood from the victim onto his clothing, you know putting him on the scene and linking him to the scene but he was in actual fact innocent.
Mr Booth’s examination of van der Westhuizen’s report implies that the defence is suggesting that there would have been multiple points at which the driver or the assailant could have come into contact with major sources of DNA evidence. Significantly, there was no DNA evidence found inside the Porsche belonging to Mthethwa, and there has been no mention of the accused’s or the deceased’s clothing having been forensically examined.
The defence’s witnesses are treating the CCTV appearances of the ‘driver’ and the assailant or ‘kicker’ as two individuals who cannot be positively identified as the same person.
Van der Westhuizen insists that major sources of DNA would have been easily transferred onto the assailant’s hands, clothes, and shoes. The crime happened over such a short period of time that it would be unrealistic to imagine any individual having time to clean themselves, or their clothing, before touching an object such as the vehicle, for example. Fluid which is not yet dry would be easily transferred onto the vehicle’s heavily stitched leather interior, or dirt-trapping floor carpets.
The visible trajectory of the driver to the vehicle, passing Kumalo on the same pavement, would have possibly exposed them to DNA. If the driver were also the assailant, DNA would have possibly been transferred onto the vehicle keys, steering wheel, carpet, accelerator and brake pedals, etc.
A major source of DNA is blood and saliva. A minor source is skin cells or ‘touch DNA’.
The State points out the lack of blood loss or open wounds in the deceased’s autopsy report, compiled by Senior Forensic Pathologist Dr Linda Liebenberg in her determination that Kumalo dies of ‘blunt force trauma’. The lack of bodily fluid would of course limit the possibility of exposure to the deceased’s DNA.
Although there was no DNA evidence found in the vehicle, there was a 20-23 day period between the assault and investigation of the vehicle. It had apparently not been washed, but there is no evidence to say that it hadn’t in fact been washed. Although biological evidence is difficult to destroy, UV light, bacterial growth caused by heat and humidity, soil, and chemicals all contribute to the degradation of DNA. Eco-friendly cleaning chemicals destroy DNA very effectively. The defence has the witness confirm if they know of any UV light, humidity, bacteria, soil, and chemicals in this particular matter having been present in, or on, the vehicle, “M’Lady I think that would be up to the Court to see if there was any evidence regarding that, I can’t say that there was or wasn’t”.
On van der Westhuizen’s training:
Van der Westhuizen’s background is given a lot of attention, a 6 page CV is supplied by Booth to this effect. Read an article here on her crime scene decontamination/cleaning business. Van der Westhuizen is a registered associate member at the International Association for Identification with membership number 28275 specialising in the field of the fingerprint [and] facial identification photography. Van der Westhuizen also has 21 years experience as a crime scene investigator and resigned from the South African Police Service on the level of lieutenant colonel and the commander of a Local Criminal Record Centre in 2013.
On van der Westhuizen’s experience specifically in DNA transfer:
van der Westhuizen: I received during my training in the DNA Recovery and Forensic Refresher Course, and that is what I base my opinion on, is that during my training in the forensic refresher and DNA recovery presented by the SAPS I learned that forensic biology is based on the Locard principle which is the same as fingerprints which means that every contact leaves a trace. The principle means that two objects that come into contact with each other will leave a trace of itself on the other object. When an assault takes place genetic material from the attacker will transfer to the victim and vice versa. According to my knowledge there is also an order of likelihood to find a DNA profile when possible physical evidence is analysed for DNA which would be in order of a major source of DNA to a minor source of DNA. This means that certain physical evidence collected on the crime scene has the potential to provide a better possibility of obtaining a DNA profile than another. The major sources of DNA would include blood, semen, saliva, tissue, bone and teeth. Your minor sources of DNA would include hair and skin cells or commonly known as touch DNA.
The State: It also, looking at your CV it would seem and correct me if I am wrong, it seems like your forte is actually fingerprints and facial recognition, am I correct?
van der Westhuizen: Yes M’Lady.
The State: And from what I have seen from your CV there is that one course, that refresher course, forensic refresher course where it seems to me you’ve got this information that you’ve testified about, am I correct, in 2012?
van der Westhuizen: Yes M’Lady I also did a forensic course previously in my earlier training in the police.
The State: Okay but are you, do you see yourself as an expert on the transfer of DNA?
van der Westhuizen: No M’Lady I wouldn’t say I am an expert, I just have a lot of experience working on crime scenes.
The State: But not on the transfer of DNA?
van der Westhuizen: No M’Lady.
On van der Westhuizen’s interpretation of the post-mortem images:
van der Westhuizen: I was able to see that possible blood or bodily fluids on the outside of the victim’s face, ears and chest area from looking at the crime scene photographs, it is not absolutely clear from the crime scene photographs or post-mortem photographs if there were any other wounds or marks on her body where blood could have surfaced to the outside of her skin or clothing as there were no pictures of the bottom of her that I could see clearly except for what was possible on the photographs. There is also some possible bodily fluids surrounding her upper body on the tar surface and then a major source of DNA would be blood or saliva and it looks like there could have been possible blood on the outside of her body on the face area and the neck area where I could see.
The State: If you look at the post-mortem report which you did, apart from a laceration on the inside of the lip there are no external wounds apart from bruises, you can go through the post-mortem report, there is only a laceration on the inside of the lip, there were no open wounds on the body, would you agree with that?
van der Westhuizen: M’Lady I looked at the crime scene photographs where I could see the marks on the outside of the deceased’s face.
The State: And do you know having looked at the video that only after the kicker and the driver has left the scene an unknown female dragged the body of the deceased and she left her at exactly where it was found and where you find your crime scene photos, have you noticed that on the CCTV footage?
van der Westhuizen: The CCTV footage that I [saw] wasn’t that far ahead, after the vehicle left that is where it stopped.
The State: Well you can take it as a fact after the person which the State alleges is the accused has driven off, an unknown female dragged the body further into the pavement and she left the body exactly where you now find the bodily fluids of the lady. In other words the point I want to make Mrs van der Westhuizen is that that what you took into account as bodily fluids which the attacker could have stepped in was not the place where she was assaulted.
If you, if one take that into account would you still say that major sources of DNA transfer was possible?
van der Westhuizen: I think so yes M’Lady.
The State: Based on what?
van der Westhuizen: On the kicking of the body or the person you know while the assault took place.
The State: Now what major sources would the kick have transferred?
van der Westhuizen: If I looked at, when I looked at the CCTV footage at some point the victim was lying on the ground and there was stomping basically from the top that looked like it was you know upwards, I mean it is really, really poor so you know I looked at what I could see and that, there was also from these photographs of the crime scene that was taken, I think it is photograph 6, you can see here on the neck area that there is reddish marks there.
The State: But what DNA would you expect to be transferred?
van der Westhuizen: That looked like possible blood to me and possible blood is a major source of DNA.
The State: Yes but you are wrong, if you look at the post-mortem and I again want to emphasise you can look at the post-mortem apart from an abrasion on the inside of the lip, the rest were all bruises.
The State: Anything else, and you also refer in your report that it seems like you assume that there must have been a transfer of DNA on the clothes of the driver, on what do you base that?
van der Westhuizen: M’Lady in the beginning of the assault that I saw on the CCTV footage, right in the beginning of it, it looks like the assailant was running like this with his arm out and the victim was in front of his arm and he was hitting her basically like that when she fell the first time. Now if he hit her around here or in the mouth area, there was definitely direct contact between him and her and then there is a good chance of transfer there.
The State: Well maybe I must just enlighten you because a previous defence witness deny (Tim Atkinson’s report) that there was any contact at that particular stage that the assailant was actually making contact with the victim so it is a bit difficult for me because we have now two scenarios in the defence case as to whether there was in fact contact at that particular point in time or not.
On the possible of the Porche having been cleaned:
The State: You said in your report that you must assume that the car was not washed, there is obviously but you wouldn’t know having only joined the case at this very late stage, but there is no evidence to that effect that the car was not washed, I mean you don’t have, you can, you accept it now in good faith?
van der Westhuizen: I wouldn’t know M’Lady.
The State: But I just want to tell you that we have no evidence to that effect. But it would seem and do I understand your report correct that even if the car was not washed it seems that the time lapse between the incident and when the car was examined, that in itself could lead to the degradation of the DNA, is that correct?
van der Westhuizen: Yes M’Lady.
On the matter of the kicker/assailant and the driver:
The State: Mrs van der Westhuizen to sum up it seems to me that you can’t tell the Court as a matter of fact that the fact that no DNA was found in the vehicle of the accused, that the kicker and the driver of the vehicle could not have been the same person, you are not in a position to tell that to the Court?
van der Westhuizen: No M’Lady.
On the clothing of the accused and the deceased:
Booth: So if let’s say clothing wasn’t tested or shoes weren’t tested, I mean what would the implication be of that, could you say?
van der Westhuizen: M’Lady I think if the clothing could have been tested and DNA evidence could have been found, it could actually have solved the case before it actually came to court for your decision. It would be a definite way of proving that the person that is arrested or accused is involved or not involved. It would be a really good piece of evidence to have in a case to prove a case or disprove a case.
The final arguments will be presented on Tuesday 22 November at 09:30.