Forensic entomology deals with the collection of arthropodic evidence and its application, and through a series of tests and previously set rules, the general admissibility of said evidence is determined. Forensic entomology may come into play in a variety of legal cases, including crime scene investigation, abuse and neglect cases, accidents, insect infestation, and food contamination.
Scientific evidence The admissibility of forensic evidence is left up to the judgment of the court. To provide a strong basis of admissibility for the evidence, accurate documentation is essential so that there is no room for speculation as to the authenticity of the evidence. Given that admissibility is granted, expert witnesses may be called to a courtroom to either support or refute the conclusions that are derived from the evidence submitted.
In order to determine what is and is not scientific evidence, a set of rules or parameters must be established for qualification. There are two basic principles that govern the acceptability of evidence.
Frye Test One of these qualifying tests is the Frye “General Acceptability” test. The Frye Standard is the test encountered more commonly in most state proceedings. The Frye Standard states that the scientific community must only accept the evidence after it is supported by a certain amount of valid information.Greenberg, Bernard & Kunich, John Charles (2002), Entomology and the Law: Flies as Forensic Indicators, New York, New York: Cambridge University Press, This test is used frequently to disqualify sketchy information such as bite mark comparisons, due to the scientific community's general belief that this can be a subjective and unreliable source and could lead to false conviction or acquittal if used in court proceedings.
Daubert Test The second test is the Daubert relevancy and reliability requirement. This federal test is applied to testimony given by expert witnesses. Despite the Daubert Standard's reliability, it is used to a lesser extent in state courts. The information provided by the witness must pass a two-part examination, it must be deemed relevant to the case at hand, and the witness must prove that it came from a reliable source. Evidence presented in court proceedings is subject to extreme scrutiny, so it is very important that the information presented to the judge and jury has been obtained using the Scientific Method. Although these two decisions have been used as standards for many years, much of the decision about what evidence makes it into the courtroom depends upon the decisions of the presiding judge.
Admissibility of evidence and judicial prudence
Information is usually admitted as evidence if it helps to clarify at least one of the five components of analyzing physical evidence: the reconstruction of events or places, identification as used in scientific tests, recognition by separating relevant and irrelevant information, individualization by proving it to be unique to a suspect or a victim, or usage of comparison analysis methods (DNA, fingerprints, etc.). All of these categories, though important, have a lot of gray areas, allowing for the judge to have the final say on what a jury can see and hear in regard to a case.
Aversion to scientific evidence
Judges tend to use more caution when admitting scientific data than when considering other types of physical evidence. This has been linked to a concern that scientific data is given priority over other forms of information. Jurors have been known to take scientific evidence as fact, so judges must decide how reliable the information is before allowing a jury to take that information into account. Allowing too much scientific data can make a case less subjective and give jurors less of a choice in their deliberation; therefore, some judges try to limit charts, graphs, and other forms of overwhelming scientific evidence in relation to a crime. This is one of the main reasons that voiceprints and polygraphs have been denied admissibility in the courtroom. They are both subjective components of scientific evidence, but if presented as fact by prosecutors, the jurors may become misinformed on how reliable the data is, and therefore most judges exclude it. These techniques are still used heavily in detective work, even though they are not admissible in court. These techniques help officers to find other types of evidence that can be brought to court and can help to ensure law enforcement that they are following the correct suspect.
Other approaches to scientific evidence that may allow its admittance One way that some judges have attempted to admit scientific evidence is in its raw form. By allowing the jury to draw their own conclusions, without confusing jargon and charts, some judges are more amicable to this approach. This requires a basic level of knowledge on how to read the data, which can be supplemented with an expert witness who may offer their own opinion. This is a less harsh approach to admitting scientific evidence.
Judges also place a large weight on the amount of corroborating evidence that can be submitted to support each piece. Typically, a judge will not admit a piece of evidence unless it can be supported by expert testimony, witnesses, or other physical evidence. One piece of evidence in a crime is somewhat meaningless. Many pieces must fit together and support the prosecution's (or the defense's) theory. Similarly, a judge will not grant admissibility to evidence that proves guilt or innocence without a doubt. This rule is eagerly applied to matters of scientific evidence because juries tend to place too much emphasis on certain evidence, particularly DNA evidence, which is believed to be foolproof. It is preferred that the circumstances are reconstructed and confirmed in small pieces. The admission of these pieces is viewed as unfair to the other counsel and is denied. The goal of the court is to leave a decision to be made by the jury after all of the evidence has been presented. Large, sweeping evidentiary discoveries take the subjectivity of the evidence out, especially in regard to scientific discoveries.
Forensic entomology as evidence in court Using forensic entomology as evidence in criminal proceedings requires the examination of a few other judicial requirements.
Federal Rules of Evidence 702 and 703 Most entomological evidence, or evidence dealing with the presence of insect larvae or adults being found at a scene, enters through expert witness testimony. Because there is little common knowledge associated with the discovery of particular larvae at a crime, it is useful for an entomologist to come in and explain what they found and what that could mean in regards to the location of death, the time of death, and other various parts of the case. This type of witness testimony enters under The Federal Rules of Evidence 702 and 703. (Daubert v. Merrell Dow Pharmaceuticals)
Use of repulsive and inflammatory evidence One rule that applies very specifically to forensic evidence is that the courts ban inflammatory or repulsive information or photographs. This can be especially difficult for entomologists because photographs of insects feeding on dead bodies tend to be controversial, but they can be crucial in making their part of the case clear. Extreme caution must be used when choosing any photographs of entomological evidence to share with a jury. This rule was put into place in order to avoid outraged jurors. Emotional responses to this type of evidence have proven to distract jurors from the issue at hand, possibly leading them to make decisions based on irrelevant data.
Other important considerations Another important factor in creating admissible entomological evidence is creating a clear and consistent chain of custody. This means that any samples taken from a body or the scene of the crime in question must have been labeled correctly and the identity of those persons who had access to it must be recorded. This record should show the location and custody of the samples at all times – from collection to analysis. Typically, an entomologist on the scene will collect their samples and lock them in their scene kit as a way of making sure that no one else has access to them to tamper with the evidence, ensuring that the information gathered in the field is viable in court. If an accurate record of custody is not kept, then the presentation of this evidence could provide a reason for appeal.
Case records and reports As is the case when collecting and handling evidence, documentation of the source, transfer, and state of said entomological evidence is crucial to a criminal investigation.Catts, E. Paul & Haskell, Neal H. (2005), Entomology & Death - A Procedural Guide, Clemson, SC: Joyce's Print Shop, Inc., An accurate record facilitates the tracking of individual pieces of evidence even if the item has been modified after the initial collection; modification can result by means of natural biological processes, like metamorphosis, or the manipulation of the insects by the lab during analysis. Accurate documentation also helps preserve the chain of custody for the evidence collected; it accounts for a detailed record of who has had access to the evidence, and the exact times and locations of when the evidence was moved and for what reason. It basically provides a step-by-step ranging from the time of collection to the court hearings.
Forensic entomologist (FE) records relating to a death scene investigation can be divided into eight categories: initial contact notes, evidence submitted, Death Scene Case Study Form, autopsy report, local weather records, Specimen Disposition and Identification Record, chain of custody record and receipts, and finally, the Case Study Final Report.
Initial Contact Notes Initial contact notes include certain preliminary information and the fee charged. The following are key pieces of preliminary information: the contact officer's name, address, and phone number; the death scene's exact location; the type of habitat in that area; the corpse's phase of decomposition; and a general description of the manner of death. When recording the information gathered, the estimated post mortem interval (PMI) made by others at the crime scene should be disregarded in order to guarantee an unbiased PMI from the entomologist. Since entomology expertise is usually requested well after the recovery of the corpse, inquiries about the kind and amount of insect activity observed and whether the body had already been moved should also be recorded. Finally, the entomologist and the law enforcement organization should mutually agree on a clear fee that appropriately covers all the services to be provided by the FE.
Evidence submitted Because it is not always possible for the forensic entomologist to be present at a crime scene to collect the appropriate evidence, it is important that clear and concise instructions are left for the handling of live and preserved specimens to those processing the scene. In these cases where the FE is not present at the scene, the transport of live and preserved specimens is necessary. As a rule, if specimens are in transport longer than an hour, they have to be kept in a chilled insulated container with enough coolant to keep them relatively inactive and stop their development. All evidence should be handled with a reasonable amount of security; from videotapes and photographs to actual specimens recovered from the field. In all cases, the evidence should be secured with a seal that ensures absolutely no tampering.
Death scene case study form