DNA evidence not enough to convict rape accused – Supreme Court of Appeal

The title and topic of this blog article is misleading, to say the least, if viewed out of context. DNA evidence is a vital tool utilized by investigators and the criminal justice system in the ongoing fight against crime and has already helped convict many offenders, including sexual offenders, in South Africa. These convictions are due to the DNA profile of a suspect and those of biological evidence collected at a crime scene matching exactly. In such cases DNA evidence in rape cases frequently leads to a conviction.

However, in a recent case before the Supreme Court of Appeal (SCA), the evidence regarding the outcome of tests carried out via the most common DNA testing method used in South Africa, and internationally, has been held to be circumstantial. An article published in Beeld (“Vrygelaatweens SA se DNS-toetse” – September 19) reported that a man convicted of raping a four-year old girl as a result of positive DNA tests has been freed. In what the report describes as a ‘directional judgment’, five judges held that evidence led about the DNA tests conducted via the so-called STR-method was circumstantial. Evidence that Sandile Bokolo’s DNA was found on the girl’s private parts could not, seen alone, prove his guilt beyond reasonable doubt. The judges pointed out that the DNA samples taken from the child matched those of at least three men, one of them being Bokolo. His conviction and 15-year sentence were set aside.

Whilst it is always disappointing to imagine that someone who may have been guilty of raping a 4 year old child is set free, it is also equally important that no one is convicted of an offence that they may not have committed. Any court must be able to show beyond reasonable doubt that the accused actually committed the crime in question. In this particular case there are a number of factors that appear to have lead to the finding by the court that insufficient evidence existed to convict Sandile Bokolo.

There are a few points which perhaps need some clarification and these include that the “so-called STR method” used in the analysis is in fact the internationally accepted and recognized methodology used in all DNA profiling of criminal cases. It is an extremely accurate science and in most instances provides irrefutable proof of who left biological evidence at a crime scene. Furthermore, the judgment does NOT indicate that ALL DNA evidence in rape cases is circumstantial evidence. Most certainly if there had been a single rapist and only one profile found in the seminal fluid found in the young girl’s body then there would be no other reasonable explanation for the presence of that person’s semen other than she must have been sexually assaulted by the suspect. In such cases additional evidence such as eye-witness testimony may not be necessary to secure a conviction.

In this case however, there was clearly a mixture of profiles from at least three men present in the fluids found emanating from the child’s private parts. In such cases it is much more difficult to say for certain that the profile of the accused exactly matches one of those found in the mixture as it is not possible to unequivocally assign profiles to the respective assailants. It is only possible to ascertain whether all the alleles (locations analysed in the DNA) of the accused’s may be accounted for by alleles found in the composite mixture. In this case there was one allele present in the profile of the accused, which was difficult to detect in the mixture. It therefore became necessary for the DNA analysts, and those providing expert testimony, to interpret whether in fact the “missing allele” was indeed present in the mixed profile obtained from the child’s body. As it could not be conclusively proven that indeed such an allele was present in the mixture, the judge ruled that there was insufficient proof to convict the accused based SOLEY on the DNA evidence.

Sadly in this case there was no other corroborating evidence such as eye-witness testimony or proof that the accused had been at, or near, the place at which the crime took place. As a result the conviction was set aside. With this in mind, it is important to remember that DNA is very seldom the ONLY form of evidence in a case. However when a DNA profile of an accused exactly matches that of a profile found at a crime scene, it provides very real and significant weight to the case and certainly places the accused at that crime scene. In such cases, where there is not a mixture of profiles present in the crime scene sample, the evidence should not be viewed as circumstantial.


One Response to “DNA evidence not enough to convict rape accused – Supreme Court of Appeal”

  1. sonwabo says:

    it amazes me how that judge convicted my friend who we where with the whole night and leave others out, to me it sounds like the state really wanted to close the case and they just did pick and chose and unfortunately SIMBONGILE was one those loyal south africans who fall under the dark side of our craby law and justice.many collidin g things were said on that court yet they sentence him and guess what he is still alive and he still praise God like never before and he is still inoccent and one the truth will come to light
    fro sonwabo one of the guys that were also taken for tests and questining