Interpol review of fingermarks and other body impressions 2016-2019

Analysis of fingermark constituents: a systematic review of quantitative studies

Fingermark identification has significance in forensic science, particularly in the processing of crime scene evidence. The majority of literature focused on physical interpretation of fingermarks with limited studies relating to chemical analysis. This systematic review investigated prospective studies dealing with the analysis of latent fingermark constituents. Studies included were those concerned with the analysis of intrinsic organic constituents present in latent fingerprints. Studies with no clear procedure were excluded. Data from the studies were exported into SPSS v22 (IBM, Armonk, NY, USA) where descriptive statistics were applied. The data extraction yielded 19 studies related to identification of lipids (n = 66) and/or amino acids (n =27) in latent fingermarks. The primary lipid identified was squalene and the major amino acids included: alanine, glycine, leucine, lysine, and serine. For identification of the aforementioned constituents both chromatographic and spectroscopic techniques of which the main technique was gas chromatography-mass spectrometry. Prior to analysis, the majority of studies involved collection of fingermarks from both hands at room temperature. Deposition was done on different substrates of which the main were glass, Mylar strips, aluminium sheets or paper. In conclusion, chemical analysis of latent fingermarks enabled identifying key biomarkers of individual that could serve as complementary evidence in crime scene investigation.

Development of a printed quality control test strip for the analysis and imaging of fingermark composition

In the last decade, there have been many scientific developments regarding the use of mass spectrometry to analyse the composition of fingermarks. In this context, the development of a dedicated quality control test strip would benefit the forensic community by providing a way to assess the reproducibility of the measures as well as to perform inter-laboratory comparisons. To accomplish this goal, the use of a chemical printer offers the possibility of combining a visual template with artificial fingerprint secretions. The design of the quality control test strip as well as the preliminary assessment of its performance with fingermark detection reagents and matrix-assisted laser desorption-ionisation combined with mass spectrometry imaging (MALDI-MSI) are presented in this paper. The chosen template combines two geometric patterns intended to help assess the chemical analysis (full square) and imaging (lined square) capabilities of the instrument. The artificial secretion is composed of two distinct solutions: artificial sweat and artificial sebum. The printing reproducibility and chemical homogeneity of the quality control test strips were assessed in two ways: (1) using MALDI-MSI, the printed pattern was analysed and the m/z values compared to the reference list based on the artificial secretion composition, and (2) using two common fingermark detection techniques, the printed pattern was processed using an amino acid reagent (ninhydrin) and a lipid stain (Oil Red O). Overall, the results highlight the potential of a printed quality control test strip for the assessment of the quality of fingermark detection techniques as well as the possibility of performing quality monitoring of mass-spectrometry-based techniques over time.

The benefit of AFIS searches of lateral palm and non-distal phalanges prints in criminal investigation

The ongoing upgrade of AFIS worldwide resulted in new achievements in the domain of fingerprint identification. Two cases are presented which depict the importance of collecting and employing a broader search in AFIS to include lateral palm prints and non-distal phalanges prints.

The impact of time, environmental conditions, and sex on the degradation of bloody fingerprints on a glass surface

Dactyloscopy is the branch of forensics that deals with identifying individuals by analyzing the configurations of the friction ridges on the fingertips. The persistence and degradation of fingerprints depends on such factors as the individual's sex and BMI (body mass index) and the duration and conditions of their preservation. There is a great deal of information on how the passage of time affects the image of fingerprints composed of sebum and sweat, but little knowledge concerning the preservation of bloody fingerprints. The aim of the study was to determine the effect of sex, the state of the blood forming the print (dry vs. fresh), environmental factors (room vs. outdoor conditions), and time on the width of friction ridge impressions in fingerprints. Fingerprints made with fresh blood were found to persist longest, while prints left by women and exposed to outdoor conditions degraded most rapidly. The ambient temperature also had a significant effect on the width of friction ridge impressions and their degradation.

Carbon Dots for Forensic Applications: A Critical Review

Owing to their superior fluorescence performance, inexpensive synthesis and nontoxic nature, carbon dots (C-dots) are systematically explored in a variety of applications; in this review, we outline and critically discuss recent trends with respect to their potential exploitation in criminal investigation, forensic toxicology and anti-counterfeit interventions. Capitalising on their colour-tuneable behaviour (in the sense that they adopt different colours with respect to the incident radiation), C-dot-based compositions are ideal for the visual enhancement of latent fingerprints, affording improved contrast against multicoloured and patterned backgrounds. As highly sensitive and highly selective optical nanoprobes, C-dots show excellent analytical performance in detecting biological compounds, drugs, explosives, heavy metals and poisonous reactants. In addition, benefiting from their versatile structural and chemical composition, C-dots can be incorporated into ink and polymeric formulations capable of functioning as a new generation of cost-effective barcodes and security nanotags for object authentication and anti-counterfeit applications. Translating these encouraging research outcomes into real-life innovations with significant social and economic impact requires an open, multidisciplinary approach and a close synergy between materials scientists, biologists, forensic investigators and digital engineers.