Situating forensic traces in time

Abstract

Situating events and traces in time is an essential problem in investigations. To date, among the typical questions issued in forensic science, time has generally been unexplored. The reason for this can be traced to the complexity of the overall problem, addressed by several scientists in very limited projects usually stimulated by a specific case. Considering that such issues are recurrent and transcend the treatment of each trace separately, the formalisation of a framework to address dating issues in criminal investigation is undeniably needed. Through an iterative process consisting of extracting recurrent aspects discovered from the study of problems encountered by practitioners and reported in the literature, common mechanisms were extracted and provide understanding of underlying factors encountered in forensic practice. Three complementary approaches are thus highlighted and described to formalise a preliminary framework that can be applied for the dating of traces, objects, persons and indirectly events.

Fingerprint composition and aging: A literature review

“…Several different research groups have explored changes to fingerprints over time [13][14][15]20,33,34,58,73,74,88,93,[95][96][97][98]108,[119][120][121][122][123][124][125][126],and numerous attempts have been made to determine an accurate method for determining the age of a fingerprint. Some of the methods first proposed are particularly unreliable however, as they focused purely on changes to physical characteristics over time [127].…”

“…Fingerprint composition changes through various chemical, biological and physical processes resulting in the aged composition. The rate and method of the aging process can vary significantly [88], with initial compounds lost through various processes including degradation, drying, evaporation, metabolism, migration, oxidation and polymerisation [3]. Recent findings exploring these changes are critically discussed in the following sections.…”

Fingermark age determinations: Legal considerations, review of the literature and practical propositions

“…Today, such dating questions are commonly asked related to other types of evidence, such as blood or DNA [60,61], and temporal questions have indeed been recognised as essential, but complex, issues for forensic science [4,5]. Weyermann and Ribaux noted that "Estimating the age of a trace is a rather difficult challenge in most cases, because ageing processes are influenced by many factors apart from time, some of them considerably accelerating or inhibiting the ageing" [4]. Thus, it is generally recognized that more research is needed in order to be able to scientifically address fingermark dating questions in practice.…”

“…However, this information is directly linked to the relevance of these marks, (i.e. if they were left during the crime by an implicated person) [4,5], and thus can be crucial for the resolution of a case. This explains why suspects often raise alternative temporal explanations (legitimate or not) for the presence of their fingermarks at the crime scene.…”

Strategies for Potential Age Dating of Fingerprints through the Diffusion of Sebum Molecules on a Nonporous Surface Analyzed Using Time-of-Flight Secondary Ion Mass Spectrometry

“…5,6 Attributing spatial information to such compounds provides new perspectives to latent fingerprint analysis that is relevant to forensics, such as the activities of the donor prior to or during deposition of the fingerprint, which may potentially aid in the reconstruction of a crime scene or may assist in its tactical investigation. 7,8 Of particular interest is to estimate the time of deposition of a fingerprint, which could be used to identify fingerprints that are related to the crime, ideally being able to assess the relevance of the evidence in a crime scene.…”