The print cannot be classified into one of the three basic fingerprint patterns. Prints may be smudged. No friction ridges are clearly defined. Print is almost completely smudged or obscured and cannot be classified into one of the three basic fingerprint patterns.
Quantitative data were described using range minimum and maximum mean, standard deviation. For normally distributed data, comparison between the two studied groups were done using independent t-test while F-test ANOVA was used and Post Hoc test LSD to compare between the three studied groups.
Yet, No prints were detected on 10th day. Regarding metal or plastic surface, no marks with good visibility were detected in day 1, 2 or 10 Table 1. The quality of the developed fingerprints on glass surfaces after 1 day revealed that half of them were of poor visibility.
Sixty percent of the prints were developed on glass surfaces with good visibility after 1 day of submersion. On the second day, only half of the developed prints were of good visibility.
On the other hand; after 10 days of submersion, most of the prints were invisible Table 3. Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals 1, 2, and 10 days on glass surface recovered from sea water.
Showing highest mean visibility score with CA. Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals 1, 2, and 10 days on metal surface recovered from sea water. Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals 1, 2, and 10 days on plastic surface CD recovered from sea water.
It shows higher mean visibility score of prints developed using CA. Regarding the metal surfaces, all the developed fingerprints showed good and very good visibility after 1 or 2 days of exposure to fresh water. On comparing the three studied techniques used for fingerprints development after submergence in fresh water, a significant difference in the majority of examined prints was noticed with the highest score when using CA Figs.
Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals 1, 2, and 10 days on glass surface recovered from freshwater. It shows that highest mean visibility score of prints developed using CA.
Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals on metal surface recovered from freshwater.
Bar graph - Comparison between the Black powder, SPR and CA development techniques at different time intervals on plastic surface recovered from freshwater. On the basis of the results; CA was found to be the best technique used for development of latent fingerprints on different dried studied materials recovered from sea or fresh water, sea water is considered more destructive to fingerprints than fresh water Table 7.
Also it was found that the quality of fingerprints developed was affected by the duration of submersion. Fingerprints are considered to be a key role and the most valued tool in crime scene investigation.
The detection of latent fingerprints is practically a challenging analytical problem, where detection of very small quantities of specific chemical compounds is required Cadd et al. Consequently, the current study was conducted to evaluate the possibility of recovery of submerged latent fingerprints on non-porous surfaces using different techniques. Black powder, SPR and CA were used in the current study as these methods are the most commonly used techniques and they are fairly adaptable in their applicability Yamashita and French The groomed fingerprints were used in the current study.
Different agencies and institutions especially in developing countries cannot afford the acquisition of fuming cabinet with programmable humidity.
In the current study; all surfaces subjected to cyanoacrylate fuming were placed under the same experimental conditions temperature, humidity and time. In order to assess the effect of water salinity fresh versus sea water on latent prints development and the effect of various methods on the same substrate, it was better to leave the surface two hours to dry before applying SPR.
The present study revealed that; successful recovery of good and very good quality of latent fingerprints is possible following submersion in different aquatic environments. Therefore, fingerprints were examined at different intervals; 1, 2 and 10 days. In the present work, either in sea or fresh water, the duration of submersion in water has its effects with a marked diminished quality of fingerprints in longer duration 10 days. However, prints of good visibility score 4 were still detected at 10th days when CA fuming was used.
This could be of practical importance during examination of such evidences whatever the nature of the surfaces. The reduced quality of developed fingerprints with increasing the time elapsed since deposition may be explained in the light of the fact that; fingerprint composition changes through various chemical, biological and physical processes resulting in the aged composition Cadd et al.
Initial compounds are lost through various processes including degradation, metabolism, migration, oxidation and polymerization. The longer aging periods may result in greater degradation of fingerprint components Girod et al. Former research exploring these changes has chiefly focused on lipid components; fatty acids, wax, esters, triglycerides, cholesterol and squalene within fingerprints, as these tend to decrease significantly in concentration over time Mong et al.
Additionally, water, bottom mud, sands and other factors can very easily cause prints to fade faster. Trapecar study Trapecar a demonstrated similar results in his study made on wet foil, where he assumed that the quality of the developed fingerprints on objects found in water would depend on the length of submersion.
Similarly, Soltyszewski et al. Soltyszewski et al. However they used; aluminum powder, ferromagnetic powder, and CA. They found a decrease in latent fingerprint visualization with increasing the duration of submersion. This may be referred to the difference in methods of visualization, temperature of water between the two studies and the effect of sand and mud on reduced quality of visualization.
The present study also demonstrated that, the highest percentage of good and very good quality score 4, 5 of fingerprints was detected when CA technique is used.
Similar results were obtained in another study by Trapecar Trapecar b , where the examined glass and metal surfaces were exposed to the influences of stagnant water during different time intervals. He concluded that, the best results were achieved with CA. Moreover, the time intervals were; 4 h, 1, 2 and 7 days. In contrast, Trapecar Trapecar a , showed that SPR is the best method for development of fingerprints from wet transparent foil surface submerged in stagnant water during different time intervals.
It could be attributed to the different nature of the surface used and to enhancement technique being applied while the surface is still wet, while in the current study various techniques were used after the surfaces being dried. A study investigated the effect of aquatic environment, as a destructive crime scene condition, on the quality of fingerprints. Water has an effect on the survivability of latent prints, and their successful development Dhall and Kapoor Sea water had more destructive effect due to its salinity; this could be explained by the good quality of fingerprints recovered from fresh water versus sea water as revealed in the current study.
The present study concluded that it is possible to recover latent prints submerged in water on different non porous dried surfaces with the best visualization method using CA either in fresh or sea water.
Also, the duration of submersion affects the quality of fingerprints developed; the longer the duration, the worse the quality is. This study showed that any piece of evidence recovered from underwater should be tested for prints, no matter the amount of time spent beneath the surface.
Almog J, Azoury M, Elmaliah Y, Berenstein L, Zaban A Fingerprints' third dimension: the depth and shape of fingerprints penetration into paper — cross section examination by fluorescence microscopy.
J Forensic Sci — PubMed Google Scholar. Guidelines for the assessment of fingermark detection techniques, IFRG version1. Archer N, Charles Y, Elliott J, Jickells S Changes in the lipid composition of latent fingerprint residue with time after deposition on a surface.
Forensic Sci Int — Sci Justice 55 4 — Article PubMed Google Scholar. Sci Justice — Bibliogov, USA. Those left fingerprints are hidden.
We cannot see them with our naked eyes. To visualize, collect, and preserve them, we have to use some developing techniques we will discuss here. To develop latent fingerprints at the scene of a crime, we can use mechanical methods that include the use of fluorescent powders or chemical methods, including iodine fuming, ninhydrin, cyanoacrylate, and silver nitrate method. In addition to the methods to develop latent prints, we will be discussing the collection and preservation of the latent prints collected to send them to the labs for its analysis.
These are laser or LED devices that emit a particular wavelength, or spectrum, of light. Some devices have different filters to provide a variety of spectra that can be photographed or further processed with powders or dye stains.
For example, investigators may use a blue light with an orange filter to find latent prints on desks, chairs, computer equipment or other objects at the scene of a break-in. Using a fluorescent dye stain and an orange alternate light source helps this latent print appear clearly so that it can be documented.
Use of various alternate light sources may help enhance the appearance of a fingerprint. Cyanoacrylate: Investigators often perform cyanoacrylate superglue processing, or fuming, of a surface before applying powders or dye stains.
This process, typically performed on non-porous surfaces, involves exposing the object to cyanoacrylate vapors. The vapors fumes will adhere to any prints present on the object allowing them to be viewed with oblique ambient light or a white light source. A chamber specially designed for exposing latent prints to super glue fumes. Super glue fumes adhere to latent fingerprints on the neck of a glass bottle.
Chemical Developers: Porous surfaces such as paper are typically processed with chemicals, including ninhydrin and physical developer, to reveal latent fingerprints. These chemicals react with specific components of latent print residue, such as amino acids and inorganic salts. Ninhydrin causes prints to turn a purple color, which makes them easily photographed.
DFO 1,2-diazafluorenone is another chemical used to locate latent fingerprints on porous surfaces; it causes fingerprints to fluoresce, or glow, when they are illuminated by blue-green light.
Paper treated with ninhydrin reagent reveals latent prints after being processed with a household steam iron. Other Collection Methods: In addition to the methods identified above, there are special techniques for capturing prints from skin, clothing and other difficult surfaces. Amido Black, a non-specific protein stain that reacts with any protein present, is typically used for developing or enhancing bloody impressions on human skin. To reveal prints on clothing, high-tech methods such as vacuum metal deposition using gold and zinc are showing promise for the investigator.
Therefore, any nondestructive investigations are performed before the evidence is treated with chemicals. For example, a ransom or hold-up note will be examined by a questioned documents expert before being treated with ninhydrin, since some formulations of ninhydrin will cause certain inks to run, thus destroying the writing.
0コメント