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Contextual Information in Forensic Investigations

The use of contextual information in forensic investigations

The criminal justice system is continuing to evolve, and the academic programs committed to teaching criminal justice studies should increasingly get involved in the delivery of courses on the forensic investigation to their students. The term forensic investigation alludes to the application of science in the establishment and investigation of facts to be used in criminal justice. Forensic investigation is a broad field and contains various subdivisions. Some field in forensic science expects professionals to objectively examine whether two pattern evidence are similar to conclude a match (Kassin, Dror, & Kukucka, 2013). They are also expected to present their conclusion by the information that is relevant to the task and free from biases. Latterly, a dearth of literature has been present on the subjective nature of pattern analysis and has drawn attention into aspects that may impact on judgment and perception. Contextual bias has been one major concern or information effects where subjective observations and decisions can be misled by inessential information and influences (Dennis, 2013). According to a report from the United States and other few experimental studies in forensics science confirms that the issues is real and emasculates the consistency of forensics and attempts must be made in order to address the issue in forensic laboratories. The scope of the issue should also be understood within the justice system. However, since forensic is a compound interaction between science and law, there are possibilities of legitimate evidence that can be discounted, conviction of innocent people and acquaintance of guilty people (Zuckerman, 2010). In reference to the recent cases, the reliability on forensic expertise has been doubted where the court’s ready acceptance and faith in forensic evidence without understanding its fallibility and limitations has been evident. This paper aims to critically discuss the use of appropriate information in forensic investigations mainly on the contextual bias context.

Contextual Bias

Human judgment heavily depends on some forensic science and mainly in the pattern analysis fields. In spite of the process that involves objective ways of analysis and a match determination in pattern analysis eventually, depends on to the examiner and is largely subjective. Therefore, cognitive psychology plays a key role in the forensic science where it highlights the possibility of an error in human observers (Twining, 1985). It is notable that these disciplines depend on subjective examinations of the examiners; thus the judgments made are vulnerable to diverse types of biases. Contextual information or bias is one of the vacillating natural influences and tendencies that can affect the examiner’s judgment.

Contextual information bias becomes evident when well-intentioned professionals are venerable to making decisions that are erroneous as a result of extraneous influences. These external influences can cause an expert to develop expectations regarding a particular outcome of an examination subconsciously (Scientific Working Group Imaging Technology, 2013). Due to the natural human tendency, it is hard to overcome the extraneous influences that bias the expert. Some of the sources of these influences can be examiners key theory of the case and which can embed an expectation of what to perceive, as well as the investigator providing surplus information than is essential to demeanor the examination (Jankun et al 2009). Communication in a forensic laboratory between colleagues can be bias the judgment examiner mainly if the forensic examiners are working on a similar case. The expert and investigators, the prosecution and police close liaison can offer explicit suggestions, whether envisioned to or not are likely to contaminate examiner objectivity (Sopinka, Bryant, & Lederman, 2009). These biases work unconsciously and without wrongful intention on an examiner. Therefore, it is evident that errors in forensic investigations cannot be termed as deliberate or due to incompetence, but are sincere and can impact dedicated forensic experts.

Concerns of contextual information

The environmental factors carry the risk of expectation and are seen as the examiner’s particular problem in consideration of the fact that the psychological principle of the perceptions that the interpretations of what is observed becomes distorted by the expectations and desires of a task. In line with the nature of forensic science and especially in pattern analysis, the contextual influences are portrayed as the renders of examiners vulnerability to errors (Kassin, et al 2013). The main concern is when these influences impacts on an examiner objectively resulting into erroneous conclusion. According to literature in this area suggestion, contextual bias is a key issue in the forensic pattern analysis field although this issue has spread out to other fields.

The professional examiner major focus is on where the print evidence has sufficient similarity in order to be able to conclude a match. Pattern analysis comprises of fingerprints identification, footwear analysis, tool mark impression hair analysis among others. It is not easy to discuss all the areas in forensic analysis (Nennstiel 2010).As a result, the literature has focused on fingerprint identification, because it remains as one of the most trusted aspects in the forensic science. In addition, in a recent fingerprint identification case, there has been and error renewal on its perceived reliability (LexisNexis, Markham; Ligertwood, & Edmond, 2010). The issue is that by focusing on the fingerprint identification, there is a possibility of result imputation to domains that are less established in the pattern analysis.

Fingermark identification process comprises of examination and observation of an individual target ridge detail in one print and the comparing it with a match target ridge detail in another print. The trust in this process depends on the fact that two fingers are similar, and there is a diversity of patterns from person to person (Edmond, & Vuille, 2014). The finger ridge patterns do not change despite illness or scarring that may occur in a person’s life and perspiration with other substances a pattern ridge is impression is left on the surface. Prints are enough information to enable an examiner to conclude identification after matching enough characteristics.

However, in the context of contextual information and mainly contextual bias, if an examiner, in this case, is biased as a result of extraneous influences, other forensic sciences can as well be biased and which mainly rely on judgment and subjective perception (Ludwig, & Fraser, 2014). In a recent study where DNA was examined with the aim of identifying whether or not a someone’s DNA coordinated a profile from a crime scene (Dror, & Cole, 2010). There was the diverse conclusion from the analyst, but more precisely tested compared to other forensic science areas. The research confirmed that DNA analysis is as well subjective to effects of bias especially while interpreting profiles when samples mix with other people’s DNA.

Case Examples

There are various cases that can be reviewed to get a clear insight on contextual information and how contextual occur in the forensic investigation. The major focus will be directed towards two cases one from Brandon Mayfield and another from Stephan Cowans.

In Brandon Mayfield case the Bombing of the Madrid train case in the year 2004 is a clear example of erroneous latent fingerprint identifications a result of contextual bias. Digital images were submitted by the Spanish police containing a latent finger print that was obtained from plastic bags of detonators to the FBI. A Muslim by name Brandon Mayfield was identified by the FBI as the bomber an issue that was further confirmed by other FBI fingerprint professionals and other experts appointed by the court. Through exceptional circumstances the error was found and the error was identified to be as a result of humans and not due to technology or methodology. The case was a high-profile one, and there was increased pressure to solve it. As a result, the examiner was influenced to match more features between the prints. The other reasons that were seen to contribute to the error included overconfidence among the latent print agency as one of the best in these issues and the urgency of the case and information about the suspect’s religious beliefs and terrorist relations.

The other case was Stephan Cowans contentious case where potential contextual bias was evident. It is still not clearly known on how Cowans became the suspect, but his name appeared because he was termed to have sold a hat to the actual perpetrators of the attempted homicide. This may have been the extraneous influence from the word go that resulted in the biasness of the rest of the investigation and forensic examination. There was a latent print found in the home where the attempted homicide took place, and it was attributed to Cowans. The naming of Cowans is said to have been a mistake and that it appeared on the print card that contained prints of the hostages for elimination. Cowans was locked for six years and later vindicated through a DNA evidence. The, In this case, the examiner was also linked with an error that he discovered his mistake, but continued to hide it throughout the trial.

The case examples above have caused several studies into the issue of contextual information mainly in the context of contextual bias. Pattern identification has been the key focus of literature (Nieuwland, & Van Berkum, 2006). In the last few years studies have been conducted in this area where the majority of them concentrate mainly on the finger print identification and others have applied forensic science professionals. In some studies, participants were aware that they were being tested while others covert with participants unaware of the experiment (Edmond, & Roberts, 2011). A small number of studies have suggested that contextual information will have more of an influence on prints that are uncertain and highly biased.

In other arguments, the issue of contextual information in the forensic investigation is prone to contextual bias that is an actual concern in the forensics. The observations made in the forensic laboratories are the most significant in the process followed by the results assessment (Pye, & Croft, 2004). In others, arguments on the contextual bias occur from the outset of the investigation mainly on the kind of choice and selection to make and evidence to collect to take back to the laboratory. However, following the fact that it is not possible to bring back the crime scene back to the laboratory the circumstances and original theory of the offense will affect the choice of selection. These choices are seen as subjects to diverse factors of bias and evidence selection has been seen as a source of continued expectation and bias within a legal culture that proof is going to implicate (Dror, Wertheim, Fraser‐Mackenzie, & Walajtys, 2012).

It is important to note that forensic evidence that is based on contextual influences has yet to be presented in courts. This maybe a rich area of challenges for the coming future and mainly depends on how the impacts are a reality (Jan, et al 2011). It is clear that although there is a divergence in the experimental research and literature variations in this regard and in spite of the inherent flaws courts still holds a sturdy faith in the forensic science, as well as, the erroneous challenges (Blake, & Lesniewicz, 2005). Therefore, this implies that the result of extraneous influences is an ultimate challenge to the defined idea that forensic science is infallible. However, it is not yet clear on the courts receptive to these serious concerns. Certainly, a professional forensic witness offers an invaluable role to the judge or jury (Woolf, 1996). The aim is to present an inference that cannot be drawn by the tier as a result of the technicality nature of the facts. Therefore, the jury together with the judge should be made aware of that an expert examiner can likely make mistakes particularly in light of recent cases and the ones presented above. These examples of contextual bias present a question on the integrity of the forensic practices and how dependable there are in conducting investigations. However, trying to proof the contamination of the results presented in a case by contextual influences is difficult because expert examiners believe that they are always right (Dror, Charlton, & Péron, 2006). In addition, aspects of forensic science cannot be used in producing a judicial error as other circumstances and factors are required.

Possible solution to contextual bias

One most possible solution is making sure that the examiners are not issued with the information regarding a case in order to ensure that they adequately complete the task with only the relevant material to avoid any form of bias. In case the information is required they should issue with only substantially enough facts that are needed to conduct the examination (Huber, 1991). Similarly, in the technical fields where CCTV video footage is used as well as computer crime investigation, more information concerning the case is a clear surely that case undoubtedly ensures a more efficient conclusion (Marcelloni, & Aksit, 2004). However, the literature that is available latterly on contextual bias is primarily focused on pattern analysis fields, and in precise fingerprint identifications. It is perceived that once a there ambiguousness and distortion in print which is largely the situation with latent prints from a crime scene, then contextual influences help to take care of the gaps where there is missing (Ribaux, Walsh, & Margot, 2006).

The uses of contextual information can be boots by using other forms of indentation such as line ups eyewitness identification. In this case, the latent print can be presented with further comparable samples for comparison with no supplementary reminiscent information in both verbal and written form (Semmler, Brewer, & Wells, 2004). In this case the examiner will be blind on the item that is true evidence. The evidence line-up has a likelihood of reducing the intrinsic belief within forensics that verified proof would inculpate. The investigators choose evidence based on how it is connected to the crime, and this move offers a continued expectation that the evidence is going to implicate. In the case of an evidence line up, the expert examiner is conversant with the fact that an increasing number of evidence is linked to the case. Thus, they are required to exhibit actual expertise and reliability (Goudge, 1999). Therefore, this move increases the chances of making sure that the right decision was made relatively than ordinary chance.


There is a problem presented in the issue for forensic science. There are differing opinions on the literature over its existence and its strong hold. Regarding recent cases, contextual bias has a potential of causing erroneous decision. Leading the solution from a judicial perspective is not possible thus; it becomes more of a procedure question. There is a need for more research on the contextual bias with an increased focus on the broader range of disciplines and possibly a compare of pattern matching and non-matching disciplines in order to be bale to get a full determinant of any influence contextual bias may have. There need to introduce the blind proficiency testing as a way of measuring the extent of the situation first. It is important to determine the extent and level of the influence properly t be able to introduce suitable procedures from the presented series.


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