CJJS

Fingerprint examination

Occean Richardson

University of Maryland University College

Introduction

Ideally, fingerprinting is one of the most efficient and enough method of criminal investigation. The technique only requires that the crime scene is scanned for the existence of the fingerprint patterns the were left as a result of contact with surfaces such as desk chairs, wood surfaces or any other surface within the crime scene. Human being possesses different fingerprint patterns that vary from one person to the other due to the difference in their DNA structure. Therefore, any fingerprint pattern that has been obtained from the crime scene would be enough for the investigation of criminal act.

There are three major types of fingerprints that can be traced from a crime scene depending on the nature of the touch. The first aspect is the Molded impression which formed as a result of touching soft surfaces such as soap wax or tar that will leave the fingerprints imprinted on them. To obtain such prints, a clear photograph is taken and ensure that all the parts of the print is cover in the photograph. The second type is the visible impression which are left as a result of contact with a surface after touching a blood, or any viscous liquid. The third category is the latent impression which are form due to skin secretion as a result of perspiration and are visible to the naked eye or nearly visible. To obtain such fingerprints, soft powders are sprayed upon the surfaces that have been observed to contain the touch. Then a tape is used to lift off the pattern formed by the power for further examination by fingerprints experts.

Latent Fingerprinting

For latent fingerprinting, Analysis, Comparison, Evaluation and Verification procedure is always performed which is the scientific method used to examine and document latent fingerprints.

The ACE-V procedure involves four major steps for full identification of a fingerprint from a crime scene. The first step is the Analysis of the fingerprints obtained as evidence from the crime scene and in my case, I have three sample different evidences from the crime scene. The are three types of the fingerprints in human being that is; the arches, the loops and whorls. My case consists of all the three types and in order to narrow down the suspect all the three evidences will have to go through the test and be compared against the original bearers (Stevenage, & Pitfield, 2016).

Analysis.

The analysis first involves a detained observation and assessment of the presented finger to determine if they are suitable for the remaining procedure since the fingerprints may not be sufficient for the process of comparison due to lack of adequate features and in that case the examination of the fingerprints will be declared unfit hence end of the procedure and a report is submitted. On the other side, if the analysis declares the fingerprints to contain enough features for the procedure then other uncertainties such as scars must be reported if found to be existing on the patterns obtained on the tape.

Comparison

Since I was presented with names of the three suspects, I would obtain the original sample from them and compare the original characteristics to those that were obtained from the crime scenes. The other alternative would be searching for the original fingerprints of the suspects from the fingerprints database such as the IAFIS which is the largest fingerprint database (Liu, Mi, Langenburg, & Wu, 2017). Comparison of the fingerprints majorly depends on the assessment of the three patterns on fingerprints whereby as a specialist, I am required to keenly observe the patterns and compare it against the original patterns of those obtained from the suspects. For a fingerprint to be declared a match the fingerprints must fully match in their patterns with more than 12 loops or patterns matching.

The above diagram is a representation of the three fingerprints that were obtained from a crime scene. The three patterns differ across the three suspects since they are completely different.

Evaluation

During evaluation there must be a full matches pattern between the original patters and the patterns obtained from the crime scene. However, mismatch may happen due to poor sample qualities leading to failure in successful comparison of the patterns. For a sample to qualify for evaluation there must be a match between at least 8 loop patterns between the crime scene samples and the suspects samples, therefore samples evidence cannot just be declared positive without that.

Verification.

This is the final step for the result to established. In this stage, another examiner or fingerprint specialist is required to go through the fingerprints and compare them according to his knowledge on fingerprinting. At this the verification specialist can either dispute the result of the first examiner or agree with them according to his own examination.

In conclusion the fingerprinting is the most efficient method of criminal investigation since all the human finger do not completely match in terms of their patterns. This process has been the most used method of criminal investigation since most of the criminals forget to wipe out their fingerprints from crime scene surfaces.

References.

Stevenage, S. V., & Pitfield, C. (2016). Fact or friction: Examination of the transparency, reliability and sufficiency of the ACE-V method of fingerprint analysis. Forensic science international, 267, 145-156.

Liu, S., Mi, Z., Langenburg, G. M., & Wu, J. (2017). Accuracy and reliability of feature selection by Chinese fingerprint examiners. Forensic sciences research, 2(4), 203-209.