Criminal Law: Expert Testimony on Fingerprint Evidence and Procedure

This assignment delves into the realm of forensic science, specifically focusing on expert testimony related to fingerprint analysis in criminal cases. The student has formulated fictitious questions and answers for both direct and cross-examination scenarios, covering situations where fingerprints are found on a dead body and on wet surfaces. The report addresses crucial aspects such as the possibility of obtaining fingerprints from a deceased individual, the admissibility of such evidence in court, and various techniques used to extract fingerprints from different surfaces, including the use of magnetic fingerprint powder, superglue fuming, and Small Particle Reagent. Furthermore, it discusses the longevity of fingerprints on a dead body and the importance of cross-examination in validating expert opinions. The assignment also highlights considerations for using specific techniques like Small Particle Reagent, providing a comprehensive overview of fingerprint evidence and its legal implications.

Formulating Questions expert testimony
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Formulating Questions expert testimony 1
Overview
For the purpose of this report, fingerprint has selected as specific forensic aspect. In the presented report,
two scenarios related to fingerprint shall be discussed where some fictitious questions be answered .
Situation 1
In this situation, some fingerprints have been found on the dead body and the following questions have
been developed based on this fictitious situation. Answers of the same are also given below.
Question 1: Is it possible to get fingerprints from a dead body?
Yes, it is possible to get the latent fingerprint of the killer from the victim’s body. Latent fingerprints can be
understood as a reproduction of friction ridges in sweat. In addition to 99% of water, some other elements such as
fatty lipids, amino acids, and salt also exist in sweat. Quality and recovery of invisible prints can be affected by
several factors such as surface conditions, environment and person’s biology (Sellers, 2012). For instance, on a
dirty surface, fingers are only likely to remove dust and do not leave an impression. In addition to this, many other
issues can be there if the skin is not smooth or is sweaty.
Question 2: Can fingerprint on the dead body be to admit as evidence in courts
Yes, US courts accept fingerprints as a reliable means of identification.
Question 3: What are the techniques that are there to get fingerprints from the dead body
Few processes have been identified which are successful in getting fingerprint from a dead body. magnetic
fingerprint powder and superglue (cyanoacrylate) fuming wand are two of these techniques. The first process
seems successful in those cases where the body is just a few hours old. Under the subjective technique, developed
prints are lifted or photographed after brushing powder on the face, ankles, and other suspected areas.
Question 4: How long fingerprint on the dead body lasts?
As per one of the studies done in 2016, fingerprints from the dead body can be fetched up to 4 days in case
of warn weather and in the case of wintertime, it lasts for 50 days (Kiger, 2018).

Formulating Questions expert testimony 2
Question 5: What does mean to cross examination of fingerprint expert and why the same is
necessary?
Once the examiner reaches to a conclusion regarding collection and evaluation of fingerprint, the results are
required to be testified and verified by another expert, where the process is named as cross-examination. Under this
process the second examiner starts the process from beginning and then match the results with earlier ones. When
both of the examiners get agree to the same point then fingerprint becomes more strong piece of evidence.
Documentation is an important thing to do while cross-examination of fingerprint experts.
Situation 2
In this situation, some fingerprints have been found on wet surface and the following questions have been
developed based on this fictitious situation. Answers of the same are also given below.
Question 1: Can fingerprints be collect from wet surfaces?
Fingerprints have various endogenous secretions such as urea, sebaceous and amino acids. Those
fingerprints that are hydrophobic remain safe even after getting wet. Many of the times, criminals throw or water to
the surface but in actual fingerprints can be collected even after that.
Questions 2: What are the techniques that are there to get fingerprints from a wet surface?
Different chemicals can be used to detect or analyzed latent and non-visible fingerprints. fluorescent
powders or other special powders can prove useful here. One has to apply such powder on the surface of the
exhibit. By doing so the power gets stick to the ingredient of the trace. The technology cannot be used in case of
latent print on wet surfaces as the fine powder is likely to accumulate due to water. In such a situation, a special
spray can be used. In other words, this is to state that to receive a latent print from wet surface Small Particle
Reagent can be used. It makes fingerprints visible (viscan.com, 2020). As soon as the print is visible the surplus
spray is required to be washed away with the help of distilled water

Formulating Questions expert testimony 3
Question 3: What instructions need to keep in mind while using Small Particle Reagent?
As SPR generates heavy soiling, the method is not advisable for porous or interiors surfaces. Nevertheless,
in other cases, it proves a good option to seek latent fingerprints from a wet surface as it visualizes the same. In
addition to this, the spray can be used as sticky tape on difficult surfaces.

Formulating Questions expert testimony 4
References
Kiger, P., J. (2018) Do a Person’s Fingerprints Change After Death? Retrieved From:
https://science.howstuffworks.com/do-persons-fingerprints-change-after-death.htm
Sellers, L., J. (2012) Can You Get Fingerprints From a Dead Body? Retrieved From:
http://crimefictioncollective.blogspot.com/2012/01/can-you-get-fingerprints-from-dead-body.html
viscan.com. (2020) Latent Fingerprints On Wet Surfaces. Retrieved From:
https://www.eviscan.com/en/glossary/latent-fingerprints-on-wet-surfaces/