The Role of Chemical Taggants in Forensic Trace Evidence

Prakash Jha^*
*Correspondence: Prakash Jha, Department of Pharmacy, Forensic Science Section, University of Delhi, Delhi, India, Email:

Introduction

The use of taggant technology to mark things so they can be identified is becoming an important part of national strategies to reduce crime. By associating an object with a specific piece of information, taggants may be able to prevent or monitor crimes. A specific "coding" element will typically be included to infer marker uniqueness, despite the fact that the material properties of a taggant will largely vary depending on the application. Continuing advancements in portable in-field analysis, nanotechnology, and material science ought to have made it possible to develop new and improved forensic marking agents because the speed, simplicity, and accuracy of coding component analysis largely determine the overall efficacy of taggants. Nevertheless, the scant amount of recent research in this field suggests otherwise. Before attempting to provide insight into the direction that forensic marking technology will take in the future, this critical review therefore examines the state of the taggants that are currently available.

The social and economic effects of organized crime in the UK are significant, amounting to about £24 billion annually. The biggest criminal offenses, according to reports, are those that involve drug trafficking (£10.7 billion), organized fraud (£8.9 billion), and acquisitive crime (£1.8 billion). The forensic science community places a high priority on the development of strategies that are capable of either preventing these crimes or assisting in their investigation, as these estimates are only based on data from crimes that have already been committed. As a result, it is likely that actual costs will be even higher [1].

Description

Forensic taggants may be regarded as one of the products that have been commercially available to reduce criminal activity the most effectively. Since 2008, the UK court system has widely accepted the use of taggant materials as evidence, and certain marking agents have contributed to the conviction of over 1,000 criminals since then. In areas where forensic taggants (such as SmartWater®) were utilized, household burglaries in London decreased by nearly 30%, according to statistics that were made public by the Metropolitan Police Service. Taggants are a category of materials that can be applied to or incorporated into an object to make it easier to identify it. This is accomplished by making each "batch" of taggant in a way that is completely unique to it. This makes it possible to register the particular molecular composition against a particular piece of information. This composition can be examined to discover the identity of the taggant and, consequently, the object it is marking once it is recovered at a later date [2].

Known for being one of the first forensic marking materials ever created; coding systems for physical taggants are based on the straightforward morphological characteristics of their components. Typically, solid particles of a particular size, appearance, or structural arrangement are used to make these taggants unique. Since basic visual techniques like low-power microscopy are typically used to conduct analysis, these encoding mechanisms may also be referred to as "graphical".

The microdot, a tiny polymer disc containing minute photographic information between 2 and 1000 micrometers in size, is one common coding element utilized in physical taggants. Text or images etched onto microdots are typically too small to see with the naked eye, but with optical magnification, they can be seen. Companies like DataDot and Microtrace have incorporated microdot technology into a variety of ink and varnish-based suspensions despite the fact that it was initially developed as a covert method of transferring data during World War II. After that, the dots that make up these suspensions are able to function as straightforward tagging mechanisms because they are imprinted with a specific numerical code. This code is then registered against a specific owner in an electronic database. The order in which these components are layered together is unique to each taggant formulation produced. The marker's identity and the batch it came from are then revealed by a visual inspection of the layers. These particles have become the most common tagging agent for the identification of post-detonation explosive materials because of their robust nature in layer construction [2,3].

In terms of coding capacity, covert usage, overall stability, or method of analysis, each of the commercially available taggant mechanisms in this review exhibits a distinct set of strengths and weaknesses. A single taggant type cannot currently be used as a universal product identification system due to these drawbacks, necessitating the use of distinct marking techniques for various purposes. However, it is important to note that major practical advancements in nanotechnology, material science, and analytical instrument portability have taken place since the establishment of the scientific technologies that underpin these coding mechanisms. Numerous research groups are currently utilizing these advancements to develop forensic tagging reagents capable of identifying any object, regardless of circumstance [4].

Nanomaterial-based encoding strategies have been the focus of a lot of research on the design of globally applicable marking systems. Due to their small size (which prevents detection and the physical alteration of marker properties), variety of potential analysis methods, and ease of formulation within traditional marking reagent media, nanoscale particles, wires, and tubes all show great potential as next-generation tagging mechanisms. Currently, spectroscopic taggants with optical properties superior to those of organic dyes or lanthanide ion complexes are being made using semiconductive quantum dot nanoparticles. Quantum dots may present an excellent opportunity to enhance the multicomponent spectral encoding mechanisms currently utilized by spectroscopic taggants because of their narrow emission wavelengths, color-tuneable signals, and environmentalindependent fluorescence properties. The relative cytotoxicity of metal ions used in the synthesis of quantum dot particles may have hindered the commercialization of this technology. Through the creation of heavy metal-free quantum dots, efforts are currently being made to lessen these potential harms to human health and the environment [5].

Conclsuion

Forensic taggants continue to play a crucial role in reducing criminal activity by authenticating objects, preventing theft, and monitoring illegal activity. This review has attempted to document the most prominent commercially available coding mechanisms used to infer identity in a wide range of products and highlight the significant capabilities of tagging materials. Even though it is abundantly clear that none of the commercial marking methods that are currently available have all of the characteristics required of a universally applicable forensic taggant, the most recent research that is the subject of this article demonstrates that coordinated efforts are being made to improve taggants.

Acknowledgment

None.

Conflict of Interest

None.

References

1. Hunter, M. Colby, Alex E. Pozhitkov and Peter A. Noble. "Accurate predictions of postmortem interval using linear regression analyses of gene meter expression data." Forensic Sci Int 275 (2017): 90-101.

Google Scholar, Crossref, Indexed at

2. Zhu, Yizhang, Likun Wang, Yuxin Yin and Ence Yang. "Systematic analysis of gene expression patterns associated with postmortem interval in human tissues." Sci Rep 7 (2017): 1-12.

Google Scholar, Crossref, Indexed at

3. Neubauer, Jacqueline, Maria Rita Lecca, Giancarlo Russo and Christine Bartsch, et al. "Exome analysis in 34 sudden unexplained death (SUD) victims mainly identified variants in channelopathy-associated genes."  Int J Legal Med 132 (2018): 1057-1065.

Google Scholar, Crossref, Indexed at

4. Gaertner, Anna, Patrick Schwientek, Peter Ellinghaus and Holger Summer, et al. "Myocardial transcriptome analysis of human arrhythmogenic right ventricular cardiomyopathy." Physiol Genomics 44 (2012): 99-109.

Google Scholar, Crossref, Indexed at

5. Tolbert, Mariah, Sheree J. Finley, Silvia D. Visonà and Shivani Soni, et al. "The thanatotranscriptome: Gene expression of male reproductive organs after death." Gene 675 (2018): 191-196.

Google Scholar, Crossref, Indexed at