Latent Fingerprint Case Study

1. Introduction

Crime affects all levels of society and leaves a permanent scar in terms of psychological and emotional impact in the memories of the victims and their families in which time cannot erase.

In this assault case, there was a violent tussle between the victim and assaulter in the street, as the assaulter had forcefully snatched the victim’s mobile phone. However, the mobile phone was dropped by the assaulter while in a hurry to escape.

Hence, in such kind of violent tussle, distinct physical evidences such as hairs and latent fingerprints would be left behind by the assaulter, as per Dr. Edmond Locard’s exchange principle: “Every contact leaves a trace” (Jackson and Jackson, 2011, ch. 3) and these distinct evidences would help

Types of Fingerprints

Fingerprints are the vital and reliable trace evidence in the investigation of criminal cases, as no one including identical twins would have the same fingerprints (Jackson and Jackson, 2011, ch. 4). There are 3 types of fingerprints which may be recovered from the crime scenes, namely: 1) Latent fingerprints, 2) Patent fingerprints and 3) Visible fingerprints (Jackson and Jackson, 2011, ch. 4). However, in this case scenario, I will be focusing on the latent fingerprints. (63 words)

Latent fingerprint is an invisible finger mark which needs various traditional and electrochromic techniques to retrieve its optimal images (Jackson and Jackson, 2011, ch. 4) (Wargacki, Lewis and Dadmun, September 2008). Basically, it is the secretion discharges through the sweat pores of our hand, which consists of water, amino acid, sebum and salt (Jackson and Jackson, 2011, ch. 4) (Wargacki, Lewis and Dadmun, September 2008). Hence, fingerprints can be easily destroyed or degraded if the law enforcement officers are not meticulous enough to discover this trace evidence within a short period. (67 words) 2.1. Types and Uniqueness of Latent Fingerprint

(34 words) Figure 2. Types of Fingerprint Ridges (Crime Scene Investigator Network (2000 - 2016))

2.2. Fingerprint Detection Techniques and factors affecting the recovery of Fingerprints Various traditional and electrochromic techniques as shown in Table 1 are applied to extract optimal visualization of latent fingerprints before the loss of fingerprints during the degradation process, which depends on the types of surfaces to recover the fingerprints (Jackson and Jackson, 2011, ch. 4) (Wargacki, Lewis and Dadmun, September 2008) (Lennard, 2001). (39 words)

However, during the recovery of latent fingerprints, we need to consider the following factors, which will affect the quality of the images (Lennard, 2001) (Beresford et al, January 2012):

1. Any other contaminants present, such as dust particles and blood;

2. Harsh environmental conditions, such as presence of heat and water;

3. Types of surface, such as non-porous or porous; and

4. Degradation of the fingerprints over time. (61