• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.294-302
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• 2017

In this study, latent fingermarks deposited in porous or non-porous surface was developed by cyanoacrylate fuming, and then the developed fingermark is enhanced by using Rhodamine 6G. Between water-based R6G and organic solvent-based R6G, author studied about which material have higher effectiveness in enhancing fingermark. In all seven types of surfaces depositing fingermark, water-based R6G have higher effectiveness in enhancing fingermark and lower surface coloring than organic solvent-based R6G. But because the surfaces found in crime scene have multicolor background and various quality, the additional study about various surfaces is needed.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.209-216
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• 2016

Latent fingerprint left on the adhesive sides of tapes can be easily found at a crime scene. Small Particle Reagents(SPR) based on iron oxide($Fe_3O_4$) is a technique for the detection of a latent fingerprint adhesive surface. In this study, found out that the causes affecting the quality of the fingerprints developed when used SPR based on iron oxide. To a suspension of 0.5g of iron oxide in 100ml of distilled water, 0.5ml or more surfactant were added can be developed latent fingerprints of good quality. In addition, using surfactants HLB(hydrophile-lipophile balance) value of 11~18 showed good contrast to the background and latent fingerprint.

• Analytical Science and Technology
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• v.36 no.2
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• pp.80-88
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• 2023

Fingerprints play a crucial role in the identification of potential suspects in criminal cases. However, determining the actual time, i.e., the time at which the fingermark was deposited, is challenging. Herein, we investigated the persistence and aging of fingerprints over time by observing the time evolution of latent fingerprints on a polystyrene box stored in a dark room. Fingerprint samples that were stored for up to two years could be detected with maximum accuracy using a black iron-oxide-based emulsion (black emulsion). To estimate the time of fingerprint deposition, fingerprint aging was studied by analyzing the lipid components of the fingerprints after their development. Cholesterol and squalene were selected as indicators of fingerprint aging, and their ratio was estimated to assess aging. In the case of fingerprint samples stored in a dark room for up to one month after deposition, the cholesterol/squalene ratio was approximately 0.01; it increased gradually to ≥ 0.1 over six months. A substantial reduction in the levels of cholesterol and squalene from the initial levels was also noted. Cholesterol and squalene were not detected after one year of storage. Thus, the extent of aging could be determined by analyzing the aging indicators for up to six months. Two cases that could cause error in the estimation of the fingerprint deposition time, namely, heating of the fingerprint sample before development and storage of the developed fingerprints in a dark room, were also investigated.

• Analytical Science and Technology
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• v.30 no.6
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• pp.312-318
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• 2017

The shelf life of 1,2-indandione/zinc (1,2-IND/Zn) solution and polyvinylpyrrolidone (PVP) solution, which are known as reagents for developing latent fingermarks deposited on the surface of thermal paper, was studied. The standard latent fingermarks used for comparisons were artificial latent fingermarks printed on thermally sensitive and non-sensitive surfaces with the same intensity. Upon treatment of standard latent fingermarks with the pre-mixed 1,2-IND/Zn and PVP solutions, the fingermarks could be successfully developed until 3 days after the preparation of the mixture. However, from the third day after mixing the reagents, blackening was observed on the surface of the thermal paper, indicating deterioration of the reagent performance. The 1,2-IND/Zn and PVP solutions separately stored without mixing in advance were mixed immediately before use, and the development efficiency of the latent fingermarks deposited on the surface of thermal paper was observed. The performance of the PVP solution decreased after 20 days from the preparation of the reagent. It was also found that the shelf life of 1,2-IND/Zn and PVP mixture was determined by the PVP solution. The effect of oxygen and moisture on the degradation of PVP was investigated. It was found that the performance of the PVP solution deteriorated because of the influence of moisture, though it was not affected by oxygen.