Analysis of fingermark constituents: a systematic review of quantitative studies

Forensic footwear examination: A systematic review of the existing literature

Systematic reviews have been shown to be useful tools mainly in terms of identifying research areas, but the approach is less common in forensic science. Systematic reviews in forensic science have generally focused on topics closely linked to medicine or to the general practice of forensic science, such as cognitive bias or misleading evidence. The value of a systematic review is dependent on its transparency and reproducibility and, it is therefore of benefit to follow established guidelines, such as those published by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). This paper applies these guidelines to conduct an effective systematic review of the types of research that have addressed forensic footwear examination. Using this approach, it was found that overall, there is a significant body of research that has been undertaken addressing forensic footwear examination, with 427 papers in the scope of the systematic review. The results showed that the largest proportion of papers published reported the use of an algorithm to produce an automated system to code footwear marks (25.1 %). However, only a small number of papers (1.2 %) related to the actual coding process with limited research into the use of footwear intelligence (2.1 %) and linking of scenes (0.7 %) which would follow on from pattern coding. Papers relating to the recovery and enhancement of footwear marks most frequently reported in the areas of casting (7.3 %), photography (6.3 %), chemical enhancement of marks in blood (5.9 %) and other chemical enhancement (5.6 %). A relatively small proportion of papers identified considered interpretation (15.5 %) and the characteristics of a footwear mark (12.2 %), with the former predominantly focused on general interpretation (5.9 %) and the latter on damage or randomly acquired features (6.1 %). Overall, the review suggested that more research is needed to address the use of footwear intelligence; to understand the properties of footwear prints used to compare and evaluate footwear marks; and to develop a robust, transparent and consistent method to interpret and express the significance of a footwear comparison. The latter would facilitate the clear and unambiguous communication of findings to the Criminal Justice System as a whole, including the expression of the uncertainty of the evidence.

Assessment of Heavy Metals Contamination and Antimicrobial Drugs Residue in Broiler Edible Tissues in Bangladesh

There are substantial public health consequences when hazardous heavy metal contaminants and antimicrobial drug residues are present in broiler edible tissues. This study aimed to assess the concentration of antimicrobial drugs and heavy metals residues in broiler meat, bones and edible composites (combinations of liver, kidney and gizzard). Samples were collected from different types of broiler farms, broiler wet meat markets and supermarkets, covering all five divisions of Bangladesh. The antimicrobial drug and heavy metal residues were analyzed by uHPLC and ICP-MS, respectively. In addition, a cross-sectional survey was conducted among broiler meat consumers in the study areas to evaluate their attitude towards the consumption of broiler meat. The survey clearly stated that broiler meat consumers in Bangladesh have a negative attitude toward the consumption of broiler meat, although all respondents reported to eat broiler meat regularly. The antibiotic with the highest prevalence of residues in broiler edible tissues was oxytetracycline, followed by doxycycline, sulphadiazine and chloramphenicol. On the other hand, all collected broiler edible tissues contained chromium and lead, followed by arsenic. The fact of the matter is that the antimicrobial drugs and heavy metals residues were found to be below the maximum residue limit (MRL), except for the lead content. In addition, the broiler meat samples from supermarkets had lower levels of antimicrobial drugs and heavy metals residue compared to the broiler meat collected from various types of farms and broiler wet meat markets. Irrespective of the source, broiler meat was found to contain antimicrobial drugs and heavy metals residues below the MRL, except for lead, suggesting that broiler meat is safe for human consumption. Therefore, raising public awareness regarding misconceptions about broiler meat consumption among consumers would be warranted.

New Horizons for Estimating the Time Since Deposition of Fingermarks: Combining Label-Free Physical Visualization and Electrochemical Characterization

The time since deposition (TSD) of latent fingermarks (LFMs) serves as "witnesses" for crime scene reconstructions. Nevertheless, existing TSD prediction approaches focused on either physical or chemical aging parameters leading to inaccurate estimation. A novel label-free protocol has been developed, where both physical ridge patterns and lipid oxide (LipOx) degradation kinetics are realized using optical microscopy and scanning electrochemical microscopy (SECM) and combined for TSD prediction. Specifically, the surface interrogation (SI)-SECM titration was utilized to monitor the LipOx degradation in LFM arrays aligned by hole array masks, through which we derived the LipOx degradation function. After establishing the relationship between several titration parameters and titrated area by experimental and numerical simulation methods, the titrated area could be reasonably estimated and subsequently used to calculate the surface coverage of LipOx. Results demonstrated that the tip transient revealed the LipOx coverage of deposited LFMs. Notably, LipOx coverage was found to increase during the first day and then decrease over time, whose degradation rate was susceptible to light. Thus, TSD candidates of an LFM could be limited to two values through the established function. Due to the nonmonotonic trend of LipOx aging, a physical parameter "the gray value ratio (GVR) of furrows to ridges" was proposed to exclude irrelevant TSD through support vector machine (SVM) classification. Ultimately, we predicted TSDs of seven LFMs with estimation errors of 2.2-26.8%. Overall, our strategy, with the outperformed capability of gleaning physical and electrochemical information on LFMs, can provide a truly label-free way of studying LFMs and hold great promise for multidimensional fingerprint information analysis.

Incorporating hydrogels into fingermark development: indicative viscosities for preserving ridge detail on paper surfaces

Water-based fingermark development treatments for paper have long been held back by loss of ridge detail due to diffusion. Viscous hydrogels (≥2224 cP) show promise as a green method of delivering chemical developers that inhibits diffusion, thereby preserving fingermark ridge detail. This is demonstrated here with starch and xanthan gum hydrogels applied to iodine-fumed fingermarks.