Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> A series of experiments were conducted to determine the physiological impact of acute sublethal molybdenum exposure to juvenile kokanee salmon (Oncorhynchus nerka Kennerlyi). Molybdenum was found to be relatively non-toxic to kokanee as the 96 h LC(50) was greater than 2,000 mg Mo l(-1). Exposure to either 25 or 250 mg Mo x l(-1) for 7 days was found to stimulate a significant 1.6- to 1.7-fold increase in ventilation which was later characterized to be dose-dependent between 5 and 250 mg Mo l(-1). Acute sublethal molybdenum exposure was found to have little or no impact on kokanee oxygen consumption at rest or immediately following a bout of forced activity or on physiological indicators of stress such as plasma lactate, sodium and cortisol. Despite these findings, prior exposure to 25 or 250 mg Mo l(-1) resulted in post-exercise loss of equilibrium and exercise-induced delayed mortality that were not observed in controls. Molybdenum accumulation in gill and liver of kokanee was also characterized. The findings of this study suggest that despite the non-toxic nature of molybdenum, acute sublethal exposure to this metal has physiological consequences to those fish exposed even for only a brief period. Further studies are needed to more fully elucidate the metabolism and mode of action of this metal in fish. <s> BIB001 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> The detection and identification of latent fingermarks remains one of the best forensic techniques for the investigation of crime. The value of fingerprint evidence for a particular investigation relies on the ability of the fingerprint technician to detect, enhance, and record the latent fingermarks that are left behind when a smooth surface is handled with the bare hands. There is a wide range of optical, physical, and chemical detection techniques available that can be employed to detect and enhance fingermarks on various surfaces. The purpose of this article is to provide an overview of the common fingerprint detection methods that are employed in routine casework. The information provided includes the general principle behind each technique, how the technique is applied, and how methods can be employed in sequence to maximise detection effectiveness. <s> BIB002 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract Small particle reagent (SPR) is a widely used method to develop latent fingerprints on non-porous and wet surfaces. Conventionally, molybdenum disulfide based SPR has been used for the development of latent fingerprints while some SPR based on other materials such as charcoal powder, zinc carbonate and titanium dioxide have been reported. Fluorescent preparations of molybdenum disulfide based SPR have also been reported. In the present work, a number of SPR based on zinc carbonate have been developed in combination with various fluorescent dyes to develop latent fingerprints on a number of non-porous surfaces. The quality of the developed fingerprints have been evaluated and found to be reproducible. The shelf life of the reagents developed is found to be acceptable for case work purposes. The relationship between the immersion period of the substrate bearing the latent fingerprints and reagent has also been examined. <s> BIB003 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract A short continuation study was done to investigate whether three fingerprint methods can recover latent fingerprints on transparent foil submerged in water. Donors intentionally placed fingerprints on transparent foil surfaces. The surfaces to be examined were exposed to the influences of stagnant water during different time intervals. Latent fingerprints were recovered with Swedish soot mixture powder, small particle reagent (SPR) and cyanoacrylate (CA). Although good results were achieved with all methods, SPR technique proved to be the best. The experiment established and confirmed that finger marks on transparent foil surfaces can be developed even after having been exposed to water for at least one week. <s> BIB004 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract A novel, fluorescent small particle reagent (SPR) based on zinc carbonate hydroxide monohydrate, ZnCO 3 ·2Zn(OH) 2 ·H 2 O – also called basic zinc carbonate – has been formulated. The other ingredients of the formulation are crystal violet dye and a commercial liquid detergent. The composition develops clear, sharp and detailed fingerprints on a large number of non-porous items, after these were immersed in water for up to 36 h. The fluorescent nature of the reagent helps enhance weak, fragmented and chance fingerprints that are often found at crime scenes. The raw materials used to prepare the SPR are cost-effective and non-hazardous. The novel formulation develops prints of a better quality as compared to the conventional, molybdenum(IV) sulfide-based composition. <s> BIB005 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Fingerprints are the world’s oldest means of individual identification, and most of the work completed by CSIs hinges on latent fingerprinting and impression evidence. Many processes are available to reveal hidden physical evidence, and this chapter provides a look at those procedures that have been scientifically proven and accepted in court. <s> BIB006 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Friction ridge examination is one of the bedrock disciplines in forensic science and has been employed for over 100 years. It is considered the pre-eminent method of individualization in forensic science. That status, however, has recently been upset by court challenges and high-profile misidentifications. Friction ridge examination will no doubt continue as a mainstay of forensic science, but changes in methodology and interpretation may be on the horizon. How the discipline weathers these changes depends on the willingness of the profession to critically examine their foundations, procedures, and methods. <s> BIB007 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Physical developer (PD) is a fingermark development technique that deposits silver onto fingermark ridges. It is the only technique currently in routine operational use that gives results on porous substrates that have been wet. There is a reasonable understanding of the working solution chemistry, but the chemical constituent(s) contained in fingermark residue that are specifically targeted by PD are largely unknown. A better understanding of the PD technique will permit a more informed selection of alternative or complementary detection methods, and greater usage in operational laboratories. Recent research by our group has shown that PD does not selectively target the lipids present in the residue. This research investigated the hypothesis that PD targets the eccrine constituents in fingermark residue. This was tested by comparison of PD and indanedione-zinc (Ind-Zn) treated natural fingermarks that had been deposited successively, and marks that had been deposited with a ten second interval in between depositions. Such an interval allows for the regeneration of secretions from the pores located on the ridges of the fingers. On fingermark depletions with no time interval between depositions, PD and Ind-Zn treated depletions successively (and comparatively) decreased in development intensity as the amount of residue diminished. Short time intervals in between successive depletions resulted in additional secretions from the pores intermittently occurring, the increased development of which was visualised by treatment with both PD and Ind-Zn. The changes in development intensity were seen with both techniques on the same split depletions in a series, comparably and proportionately. These results indicate that the components targeted by PD are contained in the material excreted by the friction ridge pores through its mirrored development with Ind-Zn. Repetition of the experiments on marks that only contained eccrine material showed good Ind-Zn development but poor results with PD. This indicates that there are other constituents contained in "natural" fingermarks that are required to be present for PD to be able to target constituents in the eccrine sweat. It may be that the required constituents in the natural residues are non-water soluble, and that these protect the eccrine constituents from solubilisation in the aqueous washes employed in the PD method. Further research is being undertaken to determine whether PD is targeting specific compounds in the pore secretions, or a mixture of compounds consisting of the eccrine material, epidermal lipids and sebaceous lipids typically present in latent fingermark residues. <s> BIB008 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract Fingerprints are considered one of the best forms of personal identification. While numerous enhancement techniques exist to develop fingerprints under various conditions, the enhancement of fingerprints exposed to sea spray aerosol (SSA) still remains problematic. 1056 fingerprints from four donors, using a depletion series and triplicate repeats, were deposited onto glass panels and exposed to SSA for 1 week and 1 month. Control prints were deposited in the same manner and left under laboratory conditions. All prints were enhanced using fingerprint enhancement techniques available to Forensic Police Officers and subsequently examined for identifiability by a Fingerprint Expert. Significantly fewer identifiable prints ( p After 1 week's exposure, all techniques enhanced over 50% of prints, except SPR white (12%), with iron (III) oxide and Wetwop™ white producing over 90% identifiable prints. Only iron (III) oxide, Wetwop™ white and SPR black returned any identifiable prints following 1 month's SSA exposure. Iron (III) oxide being significantly better ( p Iron (III) oxide suspension and Wetwop™ white were found to be superior at enhancing prints at both SSA exposure times. <s> BIB009 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> In forensic investigations, fingerprints are considered a very important type of physical evidence. Finger marks are frequently found at crime scenes. The latent fingerprints, deposited by the ridges of the finger or palm are a complex mixture of natural secretions and contaminants from the environment. The development and visualization of latent fingerprints on some rare substrates have remained a challenge to forensic scientists. Various methods are available to develop the latent fingerprints in the literature. However the traditional method for developing the fingerprints is the powdering method [1]. In this study a new material (powder) has been identified which can be used for the development of latent fingerprints present on both nonporous and porous substrate. Small particle reagent is considered to be a wet suspension method for development of latent fingerprints on broad spectrum crime scene evidence. It is sensitive to the lipid constituents of fingerprint sweat and is efficient for processing fingerprints on articles that have been accidently or intentionally wetted [2]. In regular small particle reagent, a suspension of molybdenum (IV) sulfide in a surfactant is used as a base material [3]. The crystal dimensions of molybdenum (IV) sulfide are significant for fingerprint development. The reason being that the quantum of attraction between molybdenum (IV) sulfide and the lipid deposition is influenced by the unit cell parameters of the former. However, as the base material is gray in color, the fingerprints developed on dark colored surfaces are not satisfactorily clear due to lack of contrast. A formulation based on white basic zinc carbonate, the unit cell dimensions of which are comparable to those of molybdenum (IV) sulfide, serves to overcome this problem by developing sharp fingerprints on dark colored articles [4]. Titanium dioxide may also be used for preparing a small particle reagent formulation. It develops white colored fingerprints on plastic, glass and metallic articles [5]. In this communication, we report the utility of a fluorescent fingerprint dusting composition based on Rhodamine B dye. It detects latent impressions on different porous and non-porous items. When suspended in water containing a few drops of a liquid surfactant, the composition acts as small particle reagent and lifts fingerprints on wet non-porous articles. In many countries, including India, the first responders are the police personnel, most of who are from nonscience background. A single composition which can develop latent prints on both wet and dry surfaces is deemed to be of great support to them. <s> BIB010 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Nano-sized bismuth oxybromide (BiOBr) particles are being considered for applications within the semiconductor industry. However, little is known about their potential impact on human health. In this study, we comparatively investigated the cytotoxicity of BiOBr and titanium dioxide (TiO2) nanoparticles (NPs) using human skin keratinocyte cell line (HaCaT) as a research model. Results indicate that lamellar-shaped BiOBr (length: 200 nm, width: 150 nm, and an average thickness: around 15 nm) has less toxic effects on cell viability and intracellular organelles than TiO2 (P25) NPs. BiOBr mainly induced late cell apoptosis, while for TiO2, both early apoptosis and late apoptosis were involved. Cell cycle arrest was found in cells on both NPs exposure, and more prominent in TiO2-treated cells. More cellular uptake was achieved after TiO2 exposure, particularly at 10 μg mL(-1), presence of TiO2 resulted in more than 2-fold increase in cellular granularity compared with BiOBr. Furthermore, TiO2 had a high potential to generate intracellular reactive oxygen species (ROS) in cells, where a 2.7-fold increase in TiO2 group and 2.0-fold increase in BiOBr group at the same concentration of 25 μg mL(-1). Higher cellular uptake and ROS stimulation should contribute to the more hazards of TiO2 than BiOBr NPs. This knowledge is a crucial component in the environmental and human hazard assessment of BiOBr and TiO2 NPs. <s> BIB011 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Fingerprints have been used for human identification in criminal investigation for over 100 years. The detection of invisible or latent marks at crime scenes has been one of the great scientific challenges in forensic science and there have been considerable advances in this capability. The technological age and increasing power of computing has had a major influence on fingerprint identification providing the capacity to search large databases and provide rapid identification of persons of interest. This chapter discusses the important contribution of fingerprints to criminal investigation. <s> BIB012 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract: Small particle reagent (SPR) is a technique performed to detect latent fingerprints left on wet and moist surfaces based upon the reaction between fatty acid residuals present in the traces and hydrophobic tails of the specific reagent. Those tails are linked to a hydrophilic head of zinc carbonate based formulation to give coloured precipitate. In the present study, we have prepared a novel SPR formulation constituting of zinc carbonate based on basic fuchsin dye for the development of latent fingerprints on wet surfaces. It was shown to develop clear, sharp and detailed fingerprints on non-porous surfaces after these were immersed in water for up to 45 days. The ability of the present formulations to detect weak and chance prints not only enhances its utility, but also its potentiality in forensic casework investigations. The raw materials used to prepare the SPR are cost-effective and non-hazardous. <s> BIB013 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract Small particle reagent technique is a means to develop latent fingermarks on wet, non-porous surfaces including glass, plastic, metals and adhesive sides of tape. The method is based on the adherence of fine particles of treating solution to the oily or fatty components of latent fingermark residues. The effectiveness of technique can be improved by adding fluorescent dye in treating solution. Fluorescent small particle reagent composition not only detects faint and weak prints but it also develops latent fingermarks on multi-colored surfaces. Small particle reagent technique is convenient, efficient and cost-effective method to develop latent fingermarks on wide range of substrates of forensic importance. Standardized testing of SPR formulation is also suggested. <s> BIB014 </s> Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review <s> Main text <s> Abstract Fingerprints are the most affirmative source of personnel identification and are also one of the most ubiquitous evidences found at the crime scenes. However, successful latent print recovery is not always possible from the crime scenes especially when the prints have been exposed to destructive conditions. Crime scenes are often despoiled due to destructive conditions such as arson, explosion, exposure to drainage water and soil or snow burial. Moreover, the offender often intends to destroy the fingerprint bearing crucial evidence, using these destructive forces. Furthermore, the fingerprints exposed to despoiled crime scenes are generally neglected due to the misconception of impossible recovery. In the present study, zinc carbonate, zinc oxide and titanium dioxide based fluorescent small particle reagents were formulated, compared and evaluated for the development of latent prints exposed to destructive conditions. Fresh latent prints and prints exposed to natural or simulated destructive crime scene conditions, namely, arson, explosion, burial in soil, immersion in drainage water and burial in snow were developed using the three compositions. Latent prints were successfully recovered even from the destructive crime scene simulations. Better quality prints were obtained from fresh prints, arson, soil burial and drainage water. Relatively poor results were obtained from explosion and snow burial conditions. Wet powder based suspensions were found suitable for development of fingerprints exposed to destructive conditions and the efficiency of the reagents was found in the order: TiO2 > ZnCO3 > ZnO. <s> BIB015
Developments of physical and chemical fingerprint visualizing methods for wet surface Over the years, researchers have been consistently exploring new fingerprint visualization methods, and subsequently improving them. Commonly, the selection of visualization methods relies on the nature of surface examined (i.e., porous, semi-porous, non-porous, wet, or dry), available constituents of latent fingerprints (e.g., amino and fatty acids), as well as the order of the method application    BIB007 BIB012 . In view of forensic practical caseworks, latent fingerprints can be visualized using physical and/or chemical methods  BIB007 . In this paper, discussion on the physical method, i.e., powder suspension techniques (viz. small particle reagent (SPR) and general powder suspensions), as well as chemical methods that include iodine fuming, physical developer (PD), multi-metal deposition (MMD), single metal deposition (SMD), as well as Oil Red O (ORO) will be made. The comparative fingerprint visualization methods are included in Table 1 , the details of which are discussed below. Physical visualization method: powder suspension techniques Small particle reagent SPR (wet powder suspension) was introduced to visualize latent fingerprints on non-porous objects that were accidentally or deliberately wetted BIB004 BIB006 BIB007 BIB012 BIB013 . Researchers concurrently assumed that SPR adheres to the lipid-soluble constituents of fingerprints BIB002 BIB008 BIB007 BIB014 . Such assumption was also supported by BIB009 when they reported poor performance of black and white SPR in visualizing latent fingerprints exposed to sea spray aerosol, possibly due to the lost sebaceous constituents to such exposure. Traditionally, SPR is a suspension of fine particles of molybdenum disulphide (MoS 2 ) in a mixture of water and surfactant  BIB008 BIB014 BIB012 . Other than black, SPR comes in two other color variants viz. white and fluorescent. For dark or multi-colored surfaces, the addition of fluorescing agents was suggested by  . The authors reported that Brilliant Yellow 40 gave better contrast of visualized fingerprints under excitation in the blue range of spectrum, when compared to that of Rhodamine 6G. When  investigated the best formulation of white SPR, the authors concluded that fine suspensions of zinc carbonate (0.66 g), water (20 mL), tergitol-7 (0.06 g), and dimethyl ether (55 g) provided the best quality of visualized fingerprints on dark surfaces. However, BIB015 , while formulating a novel fluorescent white SPR comprising of rose Bengal dye, reported that visualization of latent fingerprints recovered from destructive crime scene simulations using fine suspensions of titanium dioxide (TiO 2 ) prevailed over the other two combinations viz. zinc carbonate and zinc oxide. The authors also established that regardless of the formulations used, the quality of visualized fingerprints decreased with increasing period of exposure to the simulated destructive crime scenes. Similarly, BIB013 found that increased in immersion time would subsequently affect the clarity of the visualized fingerprints, irrespective of the types of surface used. The authors reported that novel SPR-basic fuschin dye formulation showed a relatively better performance in visualizing latent fingerprints on non-porous objects immersed in clean water for 45 days, when compared to that of SPR-crystal violet formulation. In addition, BIB005 reported clear, sharp, and detailed quality of visualized fingerprints on non-porous objects after those were immersed in water for up to 36 h. However, the authors did not clarify the type of water used (e.g., tap, pond, or drainage water), and whether the experiment was conducted in an indoor or outdoor setting. BIB004 investigated the recovery of fingerprints on transparent foils immersed in stagnant and cold drinking water for up to 168 h using Swedish soot mixture powder, white SPR, and cyanoacrylate fuming. The author reported that among the three visualization methods, white SPR was deemed the best method to visualize wet latent fingerprints. In cases where ninhydrin and cyanoacrylate fuming failed to perform,  recognized the potential of SPR in visualizing chlorine-exposed latent fingerprints at different levels of humidity (i.e., dry nitrogen, 60% and 100% of ambient humidity). In another study,  claimed that SPR provided sufficiently clear and identifiable quality of visualized fingerprints on metallic knife immersed in water for up to 20 days, beyond which decreased quality of visualized fingerprints was observed. BIB010 revealed that with the incorporation of fluorescent rhodamine B dye in SPR formulation, visualized fingerprints on wet non-porous objects immersed in water for 96 h were of clear, sharp, and detailed quality. However, BIB003 disclosed that fluorescent SPR formulation based on acridine orange, anthracene, and basic yellow 40 did not revealed positive fluorescent results, although acridine orange did visualize fresh fingerprints. Other than that, the authors also reported successful visualization of latent fingerprints on substrates immersed in water for 96 h using SPR formulation based on rhodamine 6G, rhodamine B, and Cyano blue. Besides offering easy and fast wet visualization, SPR is relatively convenient for any colored surfaces as the formulation can be easily substituted with wide range of fluorescent dyes. However, precautionary measures are greatly advised upon handling SPR due to the toxicities of its chemicals viz. MoS 2 and TiO 2 , as reported in the body of literature BIB001 ; International Agency for Research on Cancer 2010; National Institute for Occupational Safety and Health 2011; BIB011 . Unfortunately, despite the continuous developments of SPR formulations, review of literature reveals no specific explanation on the interactions/mechanisms between constituents of fingerprints and compounds of SPR that has enabled the successful visualization of latent fingerprints. Due to such limitation, opportunities for further exploring the theory of such interactions may prove useful. 