Current Practice in Forensic Medicine, Volume 2

John A. M. Gall, Jason Payne-James, John A. M. Gall, Jason Payne-James

• Publisher: Wiley-Blackwell
• Year: 2016
• ISBN:
  9781118456019
• Edition: 1
• Topic: Medicine
• Subtopic: Forensic Medicine

Forensic medicine is a broad and evolving field with areas of rapid progress embracing both clinical and pathological aspects of practice, in which there may be considerable overlap. This is the second volume in a series that provides a unique, in-depth and critical update on selected topics of direct relevance to those practising in the field of clinical forensic medicine and related areas including lawyers, police, medical practitioners, forensic scientists, and students.

The chapters endeavour to maintain a relevance to an international, multi-professional audience and include chapters on:

• DNA decontamination,
• The toxicity of novel psychoactive substances,
• The relevance of gastric contents in the timing of death,
• The effects of controlled energy devices,
• The main risk factors for driving impairment,
• The risk factors for harm to health of detainees in short-term custody,
• Autoerotic deaths,
• Child maltreatment and neglect, and
• The investigation of potential non-accidental head injury in children.

Also included are chapters on excited delirium syndrome, automatism and personality disorders. Two topics not generally covered in standard clinical forensic medical textbooks include a forensic anthropological approach to body recovery in potential crimes against humanity and risk management and security issues for the forensic practitioner investigating potential crimes against humanity in a foreign country.

1
DNA contamination – a pragmatic clinical view

John A.M. Gall and Denise Syndercombe Court

Contamination considerations

Forensic DNA testing has had a significant impact on the investigation of crimes. Initially developed in the mid‐1980’s by Alec Jeffreys and his group (Jeffreys, Wilson and Thein, 1985), the original ‘fingerprinting’ procedure has been modified and refined to the point where ‘DNA profiling’ has seemingly attained infallibility status (Koehler, 1993; National Research Council, 1996; Thompson, 1997). This status has been acquired and/or enhanced by its use in the exoneration of persons falsely convicted of various crimes and the subsequent successful conviction of the apparent perpetrators (Innocence Project, 1992). The concept of DNA infallibility in the investigation of crimes has, however, led to some significant miscarriages of justice. It is these exceptions that serve as a warning that the use of DNA profiling in criminal investigations requires a full understanding of the process by those employing the technology, and caution in the interpretation of the findings and their subsequent application in the legal system.

Different types of error may occur in any scientific procedure; DNA testing is no exception. DNA profiling is not and never has been infallible. There are many potential sources of error in its application. If it is to be applied competently within the legal system, all persons utilizing DNA data must have some understanding of the science behind it and of its potential sources of error. What is apparent is that many involved in the process, whether for specimen collection, testing, interpretation, application or presentation in court, have a poor understanding of DNA technology and its limitations, the potential for both error and misinterpretation, and the consequences of these when judged in a court of law. The sources of error are many and it is not our intention to examine them all. Instead, this chapter will address the issue of DNA contamination of items – other than their deliberate contamination – and consider this in relation, in particular, to the work of the forensic physician.

Does DNA contamination occur? The answer is yes, and there are some very high‐profile cases to demonstrate its occurrence – probably it occurs far more frequently than we appreciate. The following examples of accidental contamination illustrate how easy it is for contamination to occur and how DNA profiling results may too readily be accepted without question.

The ‘Phantom of Heilbronn’

Between 2007 and 2009, the German police were confronted by an apparent unknown female criminal who had been linked by DNA to some 40 crime scenes over a fifteen‐year period (BBC News, 2009; Himmelreich, 2009). These crimes, which included six homicides and various burglaries and break‐ins, had occurred in locations across Austria, France and Germany. Dubbed the ‘Phantom of Heilbronn’ following the murder of a young policewoman, Michele Kiesewetter, in Heilbronn in 2007, the hunt for this mystery female intensified and a substantial reward of €300,000 was offered for information leading to her capture. In 2009, the German police eventually unearthed the identity of the murderer and thief. The answer had been in plain sight all the time and is a stark reminder of the fallibility of DNA profiling.

In March 2009, while investigating the case of an unidentified, burned, deceased male from 2002, the Phantom’s DNA profile was detected when re‐examining the fingerprints of a male asylum‐seeker taken years earlier in order to reveal his DNA profile. The improbability of this finding resulted in the DNA test being repeated using a second swab to collect more DNA from the specimen. This time the Phantom’s DNA was not identified. The problem was revealed as one of DNA contamination and the identified DNA was that of a female worker on a production line for cotton‐tipped swabs – swabs used by various police forces across Europe to collect specimens at crime scenes.

Stefan König of the Berlin Association of Lawyers was reported (Himmelreich, 2009) to have made a very pertinent comment in relation to placing too much credence on identifying trace amounts of DNA:

What we need to avoid is the assumption that the producer of the traces is automatically the culprit. Judges tend to be so blinded by the shiny, seemingly perfect evidence of DNA traces that they sometimes ignore the whole picture. DNA evidence on a crime scene says nothing about how it got there. There is good reason for not permitting convictions on the basis of DNA circumstantial evidence alone.

His comment has proved to be correct and the question of how the DNA ‘got there’ is particularly pertinent.

The Jama case

On 21 July 2008 a young Somalian male, Farah Abdulkadir Jama, was found guilty and imprisoned for the rape of a 48‐year‐old female in a Melbourne nightclub on 15 July 2006. The sentence was for six years with a non‐parole period of four years. It was alleged that Mr Jama had sexually assaulted the woman, who had been found unconscious in a toilet cubicle, locked from the inside. Although the woman had consumed alcohol that evening, its effects were in excess of her expectations and raised the possibility that she had been drugged, presumably by her drink or drinks being spiked. Subsequent toxicological analysis did not support this assumption but did show a high blood alcohol level.

The normal procedure for cases of acute alleged sexual assault in the State of Victoria is that victims are taken to one of several designated examination suites located within some of the major metropolitan hospitals. Within these suites a forensic examination is undertaken by a forensic medical officer (FMO) or forensic physician (FP) and specimens are collected and provided to the police. This occurred in the case of this female and Mr Jama’s DNA was identified during subsequent forensic laboratory testing of biological specimens from the alleged victim. As a result, Mr Jama was found guilty of a sexual assault and sentenced to imprisonment, of which he completed approximately fifteen months prior to his being acquitted by the Court of Appeal.

The case against Mr Jama had been based on a single piece of evidence: that his DNA had been identified on a single slide preparation and associated swab collected, among other swabs, from the alleged victim when examined by the FMO. The matching DNA was, in fact, recovered from only one of two swabs taken from the endo‐cervical region of the woman and was not present on two other swabs taken from within the vagina. In addition, from the available information, his DNA did not appear to be on the alleged victim’s clothing. Also of importance was that Mr Jama had never attended the nightclub in question (based on evidence tendered to the court) and there was no evidence to suggest otherwise.

Following Mr Jama’s acquittal, the Hon. Justice Vincent undertook an enquiry on behalf of the Victorian Department of Justice (Vincent, 2010). He came to the opinion that the most likely cause for Mr Jama’s DNA appearing on the swab was as a result of contamination within the clinical examination suite. Part of the reasoning supporting this was a failure to find any evidence to suggest that Mr Jama’s DNA could have come in contact with material from the alleged victim after the swabs had been packaged in any other way, and, more significantly, that the FMO undertaking the examination of the alleged assailant had undertaken a similar examination of another woman about one day previously in the same examination suite. This female had engaged in a sexual activity with Mr Jama, an issue that had not led to any charges being placed.

It is of note that Mr Justice Vincent was of the view that:

Not only was the evidence against him [Mr Jama] ultimately revealed as inherently unreliable but, it came to be recognized, the likelihood that he had committed the offence allegedly was, at the risk of understatement, remote and found to have been perpetrated in circumstances where it seemed to be highly improbable that there was any crime at all.

Mr Justice Vincent went on to say:

In other words, the DNA evidence was, like Ozymandias’ broken statue in the poem by Shelley, found isolated in a vast desert. And like the inscription on the statue’s pedestal, everything around it belied the truth of its assertion. The statue, of course, would be seen by any reasonably perceptive observer, and viewed in its surroundings, as a shattered monument to an arrogance that now mocked itself. By contrast, the DNA evidence appears to have been viewed as possessing an almost mystical infallibility that enabled its surroundings to be disregarded. … After following this history of the proceedings against the unfortunate Mr Jama from their origins through to their disastrous conclusion of his conviction, I have been left with the deep impression that at virtually every point, and by almost everyone involved, it was handled with so little insight into the issues which it presented that no need was seen to explore further or conduct research into them. This was particularly so in the case of those involved in the legal processes. There were ample warning signs along the way that suggested that something was amiss but they were simply not read.

These views are very similar to Stefan König’s in relation to the Phantom case (discussed above) and have echoes in the case that follows. In contrast, it was the disbelief of a police officer in the Adam Scott case (discussed below) that revealed another case of contamination.

Mr Justice Vincent made a number of recommendations for change in relation to the examination facilities, specimen collection equipment and the legal processes. Importantly, as the swabs and slides used for the collection of DNA evidence were taken from readily and generally accessed trolleys located within the examination suites rather than from dedicated DNA collection kits, recommendations made were that the specimen collection equipment be kept separate from the trolleys and in locked storage accessed only by the examining doctor. Further, it was recommended that any unused specimen collection equipmen...