Solving underwater crimes: Development of latent prints made on submerged objects

Evaluation of Storage Conditions and the Effect on DNA from Forensic Evidence Objects Retrieved from Lake Water

DNA analysis of traces from commonly found objects like knives, smartphones, tapes and garbage bags related to crime in aquatic environments is challenging for forensic DNA laboratories. The amount of recovered DNA may be affected by the water environment, time in the water, method for recovery, transport and storage routines of the objects before the objects arrive in the laboratory. The present study evaluated the effect of four storage conditions on the DNA retrieved from bloodstains, touch DNA, fingerprints and hairs, initially deposited on knives, smartphones, packing tapes, duct tapes and garbage bags, and submerged in lake water for three time periods. After retrieval, the objects were stored either through air-drying at room temperature, freezing at -30 °C, in nitrogen gas or in lake water. The results showed that the submersion time strongly influenced the amount and degradation of DNA, especially after the longest submersion time (21 days). A significant variation was observed in success for STR profiling, while mtDNA profiling was less affected by the submersion time interval and storage conditions. This study illustrates that retrieval from water as soon as possible and immediate storage through air-drying or freezing before DNA analysis is beneficial for the outcome of DNA profiling in crime scene investigations.

Fingermark quality assessment, a transversal study of subjective quality scales

Fingermark detection research aims to improve the quantity and quality of fingermarks detected through the development of novel techniques. Subsequently, there is a need to evaluate these methods to determine the quality of the developed mark. Since the 1980's there has been a significant number of publications, which utilise a variety of different quality assessment methods. The introduction of common practice methods from the International Fingerprint Research Group (IFRG) aimed to implement a more standardised approach. Although these schemes are recommended as common practice, they are only guidelines. Consequentially, there is currently no universally accepted method to evaluate the enhancement techniques implemented in research. Therefore, this study aimed to collate and analyse the published protocols being used within fingermark detection research in order to better understand their application and how research is currently analysing and interpreting fingermark quality. This study comprised of manual and automatic searches of over 2000 published papers within the fingermark detection area. After thorough analysis of the articles, 396 published papers were found to have used a scale within the years spanning 1998-2022. The number of publications that report the use of a scale to assess quality for fingermark detection research has considerably increased over the last decade. However, whilst the number of publications utilising scales has increased, it is not proportional to the number of papers using the IFRG scales. The choice of scale is often institution specific and even more specific to their location. There are also numerous different adaptations of the IFRG recommended scales, as well as novel scales, which do not associate with the IFRG recommended versions being introduced the more research continues to grow. One such reason for this is investigated here, as different quality parameters are utilised within each individual scale. There is underrepresentation of these quality parameters within some of the IFRG scales, in particular the Centre for Applied Science and Technology (CAST) scale. This correlates to the considerable number of tailored approaches as authors are forced to add these parameters within the descriptions. Until there is an introduction of clear guidelines surrounding all areas of fingermark quality, from definition to parameters chosen within phases, the research area will continue to face such issues. This article recommends areas of potential study, whilst also recommending procedures that may be employed to alleviate some of the issues seen with fingermark quality evaluation.

Preliminary Study: DNA Transfer and Persistence on Non-Porous Surfaces Submerged in Spring Water

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat saliva of known DNA quantity was applied to glass slides and exposed to stagnant and flowing spring water to observe the effects on both DNA quantity and STR detection. Results supported that DNA deposited onto glass and subsequently submerged in water experienced a decrease in DNA quantity over time, yet submersion did not have as strong of a negative effect on the detected amplification product. Additionally, an increase in DNA quantity and detected amplification product from designated blank slides (no initial DNA added) could indicate the possibility of DNA transfer.

Development of Natural Luminescent Powder for the Detection of Latent Fingerprint

<b>Background and Objective:</b> Nowadays, Dyes is widely used to improve fingerprints identification test. Natural dyes are another interesting way that can be used instead of chemical dyes because of its non-toxicity and lower cost. In this research, the development of rust powder from <i>Plumeria</i> tree was applied for fingerprints identification due to its fluorescence property under UV. Rust and Small Particle Reagent (SPR), containing ZnCO<sub>3 </sub>were applied to detect hidden fingerprints on non-porous surfaces in both dried and wet condition. <b>Materials and Methods:</b> Yellowish Rust from <i>Plumeria</i> tree was extracted with ethanol, grinded, dried and then mixed with ZnCO<sub>3</sub>. Powder slurry was sprayed over fingerprint mark on different surfaces and monitored in both dried and wet condition. Visualization of fingerprint under UV was observed. Scanning microscope (SEM), UV-visible spectroscopy (UV-VIS), Fourier-Transform Infrared Spectroscopy (FTIR) and Energy-Dispersive X-ray (EDX) were also used to characterize physical and chemical properties of rust powder. <b>Results:</b> Fingerprints identification by dust technique using <i>Plumeria</i> rust powder as ingredient, provide best quality enhancement of fingerprints under UV light due to its fluorescent property, whereas a conventional technique of Small Particle Reagent technique (SPR) doesn't show fluorescent under UV. Data from SEM and FTIR show slight adhesion between zinc carbonate particles and rust powder. <b>Conclusion:</b> Fluorescence properties of rust powder is still interesting. Further improvement in powder recipe will be further investigated.

Influence of ink and smoke ATM security systems on dactyloscopy and subsequent DNA analysis after detonation

Automated Teller Machine bombings are an increasing societal problem that are often committed using Improvised Explosive Devices. The evolution in IEDs and the negative consequences for society require new security measures to prevent these crimes. Ink staining and security smoke devices are added to cash cassettes, in order to protect ATMs and prevent ATM bombings. Traces found at crime scenes, such as fingerprints and DNA, can contribute to the identification of perpetrators. However, the effect of ink staining and security smoke devices on dactyloscopy and DNA profiling is still unknown. In the current study, we demonstrate that procedures using Citrus Cleaner or sulfosalicylic acid were successful in removing ink and security smoke deposited on plastic plates but did result in the massive loss of fingerprint information as only a low number (4%) of good quality fingerprints were recovered after smoke contamination. Secondly, security ink Sun Blue ES2, but not SICPA Green and Sun Blue ES1, had a significant impact on DNA profiling success. DNA concentrations obtained from blood spiked swabs decreased with increasing ink concentration resulting in a complete loss of genotype information with the addition of ≥10 μl Sun Blue ES2. No noticeable PCR inhibition or DNA degradation was detected during quantification, but a decreased efficiency of DNA extraction could not be excluded. Security smoke, on the other hand, does not seem to have a significant influence on DNA analysis. Precautions must therefore be taken in order to avoid contaminating DNA swabs with ink during sampling. Thirdly, only a single negative impression of a glove in ink and a single glove print were able to be visualized with white fingerprint powder on detonated cash cassettes. In conclusion, the detection of glove prints and fingerprints is limited and security ink, contrary to smoke, after detonation can have a negative influence on downstream DNA analysis procedures.

Evaluation of Nile Red-Loaded Mesoporous Silica Nanoparticles for Developing Water-Soaked Fingerprints on Thermal Paper

Nile red has been an alternative reagent for detecting latent fingerprints on wetted substrates. However, the presence of methanol in nile red solution could make injury to handlers and destroy the traces on surfaces, such as texts on thermal papers. A novel small particle reagent formulation constituting of mesoporous silica nanoparticles (MSNs) based on nile red was prepared to overcome the problem. Compared with the conventional reagents Oil Red O or nile red solution, the nile red-loaded MSNs are highly selective to lipid residues of fingerprints and showed a greater ability to develop clear, sharp, and detailed fingerprints on thermal papers after these were immersed in water. In addition, it can retain texts on the thermal papers well and use only water as a solvent. These suggested that nile red-loaded MSNs are a safe, efficient, and convenient method to develop latent fingerprints on wide range of substrates of forensic importance.

Novel Safranin-Tinted Candida rugosa Lipase Nanoconjugates Reagent for Visualizing Latent Fingerprints on Stainless Steel Knives Immersed in a Natural Outdoor Pond

Waterways are popular locations for the disposition of criminal evidence because the recovery of latent fingerprints from such evidence is difficult. Currently, small particle reagent is a method often used to visualize latent fingerprints containing carcinogenic and hazardous compounds. This study proposes an eco-friendly, safranin-tinted Candida rugosa lipase (triacylglycerol ester hydrolysis EC 3.1.1.3) with functionalized carbon nanotubes (CRL-MWCNTS/GA/SAF) as an alternative reagent to the small particle reagent. The CRL-MWCNTS/GA/SAF reagent was compared with the small particle reagent to visualize groomed, full fingerprints deposited on stainless steel knives which were immersed in a natural outdoor pond for 30 days. The quality of visualized fingerprints using the new reagent was similar (modified-Centre for Applied Science and Technology grade: 4; p > 0.05) to small particle reagent, even after 15 days of immersion. Despite the slight decrease in quality of visualized fingerprints using the CRL-MWCNTS/GA/SAF on the last three immersion periods, the fingerprints remained forensically identifiable (modified-Centre for Applied Science and Technology grade: 3). The possible chemical interactions that enabled successful visualization is also discussed. Thus, this novel reagent may provide a relatively greener alternative for the visualization of latent fingerprints on immersed non-porous objects.

Development of latent fingerprints on non-porous surfaces recovered from fresh and sea water

BACKGROUND

Criminal offenders have a fundamental goal not to leave any traces at the crime scene. Some may suppose that items recovered underwater will have no forensic value, therefore, they try to destroy the traces by throwing items in water. These traces are subjected to the destructive environmental effects. This can represent a challenge for forensic experts investigating fingerprints.

METHODS

The present study was conducted to determine the optimal method for latent fingerprints development on dry non-porous surfaces submerged in aquatic environments at different time interval. The quality of the developed fingerprints depending on the used method was assessed. In addition, two factors were analyzed in this study; the effects of the nature of aquatic environment and the length of submerged time. Therefore, latent fingerprints were deposited on metallic, plastic and glass objects and submerged in fresh and sea water for 1, 2, and 10 days. After recovery, the items were processed by black powder, small particle reagent and cyanoacrylate fuming and the prints were examined. Each print was evaluated according to fingerprint quality assessment scale.

RESULTS

Cyanoacrylate developed latent prints found to have the highest mean visibility score after submersion in fresh and sea water for 1, 2 and 10 days. Mean visibility score of prints developed showed significant decline after 10 days of submersion. Prints submerged in fresh water showed significantly higher mean visibility score than those submerged in sea water using various methods of development and in all time intervals.

CONCLUSION

The study demonstrated that it is possible to recover latent prints submerged in water on different studied dry non porous surfaces with the best visualization method using cyanoacrylate either in fresh or sea water. The duration of submersion affects the quality of fingerprints developed; the longer the duration, the worse the quality is. In addition, this study has revealed that the exposure to high salinity i.e. sea water has more damaging influence on the quality of detected fingerprints. It is concluded that any piece of evidence recovered from underwater should be tested for prints, no matter the amount of time spent beneath the surface.

Application of acid-modified Imperata cylindrica powder for latent fingerprint development

A novel powdering material that utilizes acid-modified Imperata cylindrica (IC) powder for the development of fingermarks was studied. Experiments were carried out to determine the suitability, adherence quality and sensitivity of the acid-modified IC powder. Fingermarks of different constituents (eccrine, sebaceous and natural fingermarks) on different types of surfaces were used. Acid-modified IC powder was also used to develop fingermarks of different ages as well as aged fingermarks recovered from the water. From the visual inspection, acid-modified IC powder was able to interact with different fingermark constituents and produced distinct ridge details on the examined surfaces. It was also able to develop aged fingermarks and fingermarks that were submerged in water. A statistical comparison was made against the Sirchie® Hi-Fi black powder in terms of the powders' sensitivity and quality of the developed natural fingermarks. The image quality was analyzed using MITRE's Image Quality of Fingerprint (IQF) software. From the experiments, acid-modified IC powder has the potential as a fingermark development powder, although natural fingermarks developed by Sirchie® black powder showed better quality and sensitivity based on the results of the statistical comparison.