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Visualization of latent fingerprints using silica gel G: A new technique
Egyptian Journal of Forensic Sciences (2012) xxx, xxx–xxx
Contents lists available at SciVerse ScienceDirect
Egyptian Journal of Forensic Sciences journal homepage: www.ejfs.org
ORIGINAL ARTICLE
Visualization of latent fingerprints using silica gel G: A new technique Kulvir Singh, Sahil Sharma, Rakesh K. Garg
*
Department of Forensic Science, Punjabi University, Patiala 147002, India Received 25 July 2012; revised 17 September 2012; accepted 28 September 2012
KEYWORDS Latent fingerprints; Development; Silica gel G powder; Substrates; Powder method; Conventional powders
Abstract There are various methods available for the development of latent fingerprints on different substrates. This paper presents a new powder method for the development of latent fingerprints on different substrates. In this study, a less expensive, simple and easily available, silica gel G powder (usually used in TLC plates preparation) has been used to develop the latent fingerprints on eight commonly encountered different substrates i.e., plastic, glass, ordinary mirror and metallic substrates, aluminium foil sheet, carbon paper, matchbox, cardboard, glossy-painted wooden substrates, top and writable surface of CD and glazed coloured magazine paper surface. It is observed that it gives very clear results on most of the substrates with clear ridges. ª 2012 Forensic Medicine Authority. Production and hosting by Elsevier B.V. All rights reserved.
1. Introduction In forensic investigations, fingerprints are considered a very valuable type of physical evidence. Fingerprints are found in majority of the 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. Three types of glands are responsible for the natural secretions of the skin: the sudoriferous eccrine, apocrine glands, and the sebaceous glands. These three types of glands have well-defined functions, and the composition of their secretions varies
* Corresponding author. Mobile: +91 9417522223; fax: +91 1752283073. E-mail address: [email protected] (R.K. Garg). Peer review under responsibility of Forensic Medicine Authority.
Production and hosting by Elsevier
in consequence. The sudoriferous glands are distributed all over the body and produce sweat that consists of more than 98% water.1 The composition of latent print residue includes: chloride, calcium, sulphur, urea, lactic acid, amino acids, phenol, sodium, potassium, and ammonia, cholesterol, free fatty acids, wax esters with diglycerides, triglycerides, etc.2 The development and visualization of latent fingerprints on some unusual substrates have remained a challenge to forensic scientists. Various methods are available to develop the latent fingerprints in the literature. Recently the hydrophobic silica based particles had been developed to visualise latent fingerprints.3 However the traditional method for developing the fingerprints is the powdering method.4 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 substrates. In this work silica gel G powder, that is used to prepare the thin layer chromatography (TLC) plates, is used. This powder is easily available for the laboratory work. Silica gel G powder is a form of silicon dioxide (silica) with the binder gypsum. The silicon atoms are joined via oxygen
2090-536X ª 2012 Forensic Medicine Authority. Production and hosting by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
2 atoms in a giant covalent structure. At the surface of the silica gel, the silicon atoms are joined to –OH groups. This diagram shows a small part of the silica surface.5
K. Singh et al. Silica gel G powder has not been reported as a single developing powder for fingerprints while some communications exist on the application of silica gel G as a carrier.18 It is therefore thought to undertake the present investigation and it is expected that it will provide useful information to the fingerprint experts. 2. Materials and methods
The surface of the silica gel is very polar and, because of the –OH groups, can form hydrogen bonds with suitable compounds around it as well as vander Waals dispersion forces and dipole–dipole attractions.5 In addition to these different studies have been reported by various workers.6–17
The latent fingerprints were collected on fifteen different substrates which include porous as well as non-porous surfaces. The latent fingerprints were deposited on various substrates as mentioned below and it was made sure that the subject was heavily sweating while depositing the fingerprints even in winters under laboratory conditions and all the 10 fingers were employed for taking the prints. During depositing of fingerprints, donors and substrates uniformity was maintained. The non-porous substrates used in this work are plastic (bottle plastic, transparency sheet, and gift wrapping
Figure 1 Showing comparative visualization of latent fingerprints on plastic surface with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 2 Showing comparative visualization of latent fingerprints on glass surface with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 3 Showing comparative visualization of latent fingerprints on ordinary mirror with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Visualization of latent fingerprints using silica gel G:A new technique
3
Figure 4 Showing comparative visualization of latent fingerprints on brown glass bottle with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 5 Showing comparative visualization of latent fingerprints on aluminium foil sheet with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 6 Showing comparative visualization of latent fingerprints on a transparency sheet with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 7 Showing comparative visualization of latent fingerprints on perfume can with silica gel G powder (a) white powder (b) light grey powder (c).
plastic paper), glass (plain glass and brown bottle glass), ordinary mirror, metallic substrates (perfume can and currency
coin), aluminum foil sheet, gloss-painted wooden substrates, top and writable surface of CD, polythene and a semi-porous
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
4
K. Singh et al.
Figure 8 Showing comparative visualization of latent fingerprints on CD’s top surface with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 9 Showing comparative visualization of latent fingerprints on CD’s writable surface with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 10 Showing comparative visualization of latent fingerprints on gift wrapping plastic paper with silica gel G powder (a) white powder (b) light grey powder (c).
glazed coloured magazine paper surface. The porous substrates used in this work are carbon paper (writing and inked surface), matchbox, white paper, currency note and cardboard. The prints were left for half an hour in the laboratory conditions at room temperature after deposition. The experiment was conducted in the mid of the months of February and March. The temperature and relative humidity during these months ranged from 10 to 25 C and 50.2% to 51.4%, respectively. The silica gel G powder (white in colour) manufactured by Merck Specialties Private Limited was used to develop the latent fingerprints on all the different substrates. The ordinary brushing method was not used in this work.
Few grams of the silica gel G powder was taken on the clean and dry glass plate and then the powder layer was flattened using the glass rod. The latent fingerprint was developed by slightly pressing the latent fingerprint bearing surface on the silica gel G powder layer. It is a physical method of enhancement of latent prints and works on the mechanical adherence of the fingerprint powder particles to the oily components of the skin ridge deposits. Application of powder to the print by brushing is a simple and an easy technique but it also has disadvantages that the brush on coming in contact with the surface having the print destroys the print and hence the ridge characteristics get destroyed. The excess of powder was removed by gently tapping the surface. The conventional powders available in finger-
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Visualization of latent fingerprints using silica gel G:A new technique
5
Figure 11 Showing comparative visualization of latent fingerprints on carbon paper with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 12 Showing comparative visualization of latent fingerprints on glazed coloured magazine paper with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 13 Showing visualization of latent fingerprints with silica gel G powder on glossy-painted wooden substrates (a) currency coin (b) matchbox (c) and cardboard (d).
print kit such as white powder, lightning grey powder and black powder were used for comparative study. 3. Results and discussion The results of the present studies are shown in Figs. 1–13. The latent fingerprints on different substrates were successfully developed by using silica gel G powder in majority of the cases. It was interesting to note that the silica gel G powder gives better results on contrast substrates. The latent fingerprints pres-
ent on substrates such as plastic, glass, ordinary mirror, and metallic substrates, aluminium foil sheet, carbon paper, matchbox, cardboard, gloss-painted wooden substrates, top and writable surface of CD and glazed coloured magazine paper surface, were developed and showed clear ridges as is evident from the figures. It has been found that latent fingerprints on cardboard were also visible after development and using this method the ridges were clear to read. It has also been found that after developing the latent fingerprint on the top and writable surface of CD, the data in the CD were not affected and it
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
6 could still be read. The negative results were obtained on white paper, currency note and polythene due to poor contrast. Further, this powdering method gives better results on contrast surfaces as compared to others. 4. Conclusion It is concluded from the present investigation that silica gel G powder can be used to develop the fingerprint on multicoloured surfaces and give equivalent results as those of the conventional powders. It can provide a good substitute for fingerprint visualization in comparison particularly to other powders, under the instances of scarcity.
Acknowledgements The authors are highly thankful to each and every individual who contributed samples for the present study. The senior author gratefully acknowledges the assistance rendered by the Lecturer Mr. Jaswinder Singh, Department of Forensic Science, Punjabi University, Patiala. References 1. Champod Christophe, Lennard Chris, Margot Pierre, Stoilovic Milutin. Fingerprints and other ridge skin impressions. Boca Raton, London, New York, Washington, DC: CRC Press; 2004 chapter 4. 2. Lee Henry C, Gaensslen RE. Advances in fingerprint technology. 2nd ed. Boca Raton, London, New York, Washington, DC: CRC Press; 2001 chapter 3. 3. Theaker Brenden J, Hudson Katherine E, Rowell Frederick J. Doped hydrophobic silica nano- and micro-particles as novel agents for developing latent fingerprints. Forensic Sci Int 2008;174:26–34.
K. Singh et al. 4. Sodhi GS, Kaur J. Powder method for detecting latent fingerprints: a review. Forensic Sci Int 2001;120:172–6. 5. http://www.chemguide.co.uk/analysis/chromatography/thinlayer. html. 6. Bridges BC. Practical fingerprinting. New York: Funk & Wagnalls Publishing Company; 1963, p. 250–3. 7. Graham D. Some technical aspects of demonstration and visualization of fingerprints on human skin. J Forensic Sci 1969;14(1):1–12. 8. Goode GC, Morris JR, Margot Pierre, Stoilovic Milutin. A review of their origin, composition and methods of detection. Aldermaston: AWRE; 1983, Report No. O 22/83. 9. Bridges BC. Practical fingerprinting. New York: Funk and Wagnalls Company Inc.; 1963. 10. Sodhi GS, Kaur J. Novel, cost effective organic fingerprint powder based on phloxine B dye. Def Sci J 2000;50(2):213–5. 11. Kerr FM, Haque F, Barson IW. Organic based powders for latent fingerprint detection on smooth surfaces. Part I. Can Soc Forensic Sci Int 1983;16:39–44. 12. Sodhi GS, Kaur J, Garg RK. A fingerprint powder formulation based on rhodamine B. J Forensic Ident 2003;53(5):551–5. 13. Gabay Almog J. Chemical reagents for the development of latent fingerprints. III. Visualization of latent fingerprints by fluorescent reagents in vapor phase. J Forensic Sci 1980;25(2):408–10. 14. Sodhi GS, Kaur J. A novel, cost effective organic fingerprint powder based on fluorescent eosin yellow dye. Indian J Criminol 1999;27(3–4):73–4. 15. Howard S. Basic fuchsin – a guide to one step processing for black electrical tape. J Forensic Sci 1993;38(6):1391–403. 16. Sodhi GS, Kaur J, Garg RK. Fingerprint powder formulation based on basic fuchsin dye. J Forensic Med Toxicol 2004;21(1):8–9. 17. Garg RK, Kumari Harish, Kaur Ramanjit. A new technique for visualization of latent fingerprints on various substrates using powder from turmeric: a rhizomatous herbaceous plant (Curcuma longa). Egypt J Forensic Sci 2011;1:53–7. 18. http://www.freepatentsonline.com/4176205.html.
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Contents lists available at SciVerse ScienceDirect
Egyptian Journal of Forensic Sciences journal homepage: www.ejfs.org
ORIGINAL ARTICLE
Visualization of latent fingerprints using silica gel G: A new technique Kulvir Singh, Sahil Sharma, Rakesh K. Garg
*
Department of Forensic Science, Punjabi University, Patiala 147002, India Received 25 July 2012; revised 17 September 2012; accepted 28 September 2012
KEYWORDS Latent fingerprints; Development; Silica gel G powder; Substrates; Powder method; Conventional powders
Abstract There are various methods available for the development of latent fingerprints on different substrates. This paper presents a new powder method for the development of latent fingerprints on different substrates. In this study, a less expensive, simple and easily available, silica gel G powder (usually used in TLC plates preparation) has been used to develop the latent fingerprints on eight commonly encountered different substrates i.e., plastic, glass, ordinary mirror and metallic substrates, aluminium foil sheet, carbon paper, matchbox, cardboard, glossy-painted wooden substrates, top and writable surface of CD and glazed coloured magazine paper surface. It is observed that it gives very clear results on most of the substrates with clear ridges. ª 2012 Forensic Medicine Authority. Production and hosting by Elsevier B.V. All rights reserved.
1. Introduction In forensic investigations, fingerprints are considered a very valuable type of physical evidence. Fingerprints are found in majority of the 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. Three types of glands are responsible for the natural secretions of the skin: the sudoriferous eccrine, apocrine glands, and the sebaceous glands. These three types of glands have well-defined functions, and the composition of their secretions varies
* Corresponding author. Mobile: +91 9417522223; fax: +91 1752283073. E-mail address: [email protected] (R.K. Garg). Peer review under responsibility of Forensic Medicine Authority.
Production and hosting by Elsevier
in consequence. The sudoriferous glands are distributed all over the body and produce sweat that consists of more than 98% water.1 The composition of latent print residue includes: chloride, calcium, sulphur, urea, lactic acid, amino acids, phenol, sodium, potassium, and ammonia, cholesterol, free fatty acids, wax esters with diglycerides, triglycerides, etc.2 The development and visualization of latent fingerprints on some unusual substrates have remained a challenge to forensic scientists. Various methods are available to develop the latent fingerprints in the literature. Recently the hydrophobic silica based particles had been developed to visualise latent fingerprints.3 However the traditional method for developing the fingerprints is the powdering method.4 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 substrates. In this work silica gel G powder, that is used to prepare the thin layer chromatography (TLC) plates, is used. This powder is easily available for the laboratory work. Silica gel G powder is a form of silicon dioxide (silica) with the binder gypsum. The silicon atoms are joined via oxygen
2090-536X ª 2012 Forensic Medicine Authority. Production and hosting by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
2 atoms in a giant covalent structure. At the surface of the silica gel, the silicon atoms are joined to –OH groups. This diagram shows a small part of the silica surface.5
K. Singh et al. Silica gel G powder has not been reported as a single developing powder for fingerprints while some communications exist on the application of silica gel G as a carrier.18 It is therefore thought to undertake the present investigation and it is expected that it will provide useful information to the fingerprint experts. 2. Materials and methods
The surface of the silica gel is very polar and, because of the –OH groups, can form hydrogen bonds with suitable compounds around it as well as vander Waals dispersion forces and dipole–dipole attractions.5 In addition to these different studies have been reported by various workers.6–17
The latent fingerprints were collected on fifteen different substrates which include porous as well as non-porous surfaces. The latent fingerprints were deposited on various substrates as mentioned below and it was made sure that the subject was heavily sweating while depositing the fingerprints even in winters under laboratory conditions and all the 10 fingers were employed for taking the prints. During depositing of fingerprints, donors and substrates uniformity was maintained. The non-porous substrates used in this work are plastic (bottle plastic, transparency sheet, and gift wrapping
Figure 1 Showing comparative visualization of latent fingerprints on plastic surface with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 2 Showing comparative visualization of latent fingerprints on glass surface with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 3 Showing comparative visualization of latent fingerprints on ordinary mirror with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Visualization of latent fingerprints using silica gel G:A new technique
3
Figure 4 Showing comparative visualization of latent fingerprints on brown glass bottle with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 5 Showing comparative visualization of latent fingerprints on aluminium foil sheet with silica gel G powder (a) white powder (b) light grey powder (c) black powder (d).
Figure 6 Showing comparative visualization of latent fingerprints on a transparency sheet with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 7 Showing comparative visualization of latent fingerprints on perfume can with silica gel G powder (a) white powder (b) light grey powder (c).
plastic paper), glass (plain glass and brown bottle glass), ordinary mirror, metallic substrates (perfume can and currency
coin), aluminum foil sheet, gloss-painted wooden substrates, top and writable surface of CD, polythene and a semi-porous
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
4
K. Singh et al.
Figure 8 Showing comparative visualization of latent fingerprints on CD’s top surface with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 9 Showing comparative visualization of latent fingerprints on CD’s writable surface with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 10 Showing comparative visualization of latent fingerprints on gift wrapping plastic paper with silica gel G powder (a) white powder (b) light grey powder (c).
glazed coloured magazine paper surface. The porous substrates used in this work are carbon paper (writing and inked surface), matchbox, white paper, currency note and cardboard. The prints were left for half an hour in the laboratory conditions at room temperature after deposition. The experiment was conducted in the mid of the months of February and March. The temperature and relative humidity during these months ranged from 10 to 25 C and 50.2% to 51.4%, respectively. The silica gel G powder (white in colour) manufactured by Merck Specialties Private Limited was used to develop the latent fingerprints on all the different substrates. The ordinary brushing method was not used in this work.
Few grams of the silica gel G powder was taken on the clean and dry glass plate and then the powder layer was flattened using the glass rod. The latent fingerprint was developed by slightly pressing the latent fingerprint bearing surface on the silica gel G powder layer. It is a physical method of enhancement of latent prints and works on the mechanical adherence of the fingerprint powder particles to the oily components of the skin ridge deposits. Application of powder to the print by brushing is a simple and an easy technique but it also has disadvantages that the brush on coming in contact with the surface having the print destroys the print and hence the ridge characteristics get destroyed. The excess of powder was removed by gently tapping the surface. The conventional powders available in finger-
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
Visualization of latent fingerprints using silica gel G:A new technique
5
Figure 11 Showing comparative visualization of latent fingerprints on carbon paper with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 12 Showing comparative visualization of latent fingerprints on glazed coloured magazine paper with silica gel G powder (a) white powder (b) light grey powder (c).
Figure 13 Showing visualization of latent fingerprints with silica gel G powder on glossy-painted wooden substrates (a) currency coin (b) matchbox (c) and cardboard (d).
print kit such as white powder, lightning grey powder and black powder were used for comparative study. 3. Results and discussion The results of the present studies are shown in Figs. 1–13. The latent fingerprints on different substrates were successfully developed by using silica gel G powder in majority of the cases. It was interesting to note that the silica gel G powder gives better results on contrast substrates. The latent fingerprints pres-
ent on substrates such as plastic, glass, ordinary mirror, and metallic substrates, aluminium foil sheet, carbon paper, matchbox, cardboard, gloss-painted wooden substrates, top and writable surface of CD and glazed coloured magazine paper surface, were developed and showed clear ridges as is evident from the figures. It has been found that latent fingerprints on cardboard were also visible after development and using this method the ridges were clear to read. It has also been found that after developing the latent fingerprint on the top and writable surface of CD, the data in the CD were not affected and it
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001
6 could still be read. The negative results were obtained on white paper, currency note and polythene due to poor contrast. Further, this powdering method gives better results on contrast surfaces as compared to others. 4. Conclusion It is concluded from the present investigation that silica gel G powder can be used to develop the fingerprint on multicoloured surfaces and give equivalent results as those of the conventional powders. It can provide a good substitute for fingerprint visualization in comparison particularly to other powders, under the instances of scarcity.
Acknowledgements The authors are highly thankful to each and every individual who contributed samples for the present study. The senior author gratefully acknowledges the assistance rendered by the Lecturer Mr. Jaswinder Singh, Department of Forensic Science, Punjabi University, Patiala. References 1. Champod Christophe, Lennard Chris, Margot Pierre, Stoilovic Milutin. Fingerprints and other ridge skin impressions. Boca Raton, London, New York, Washington, DC: CRC Press; 2004 chapter 4. 2. Lee Henry C, Gaensslen RE. Advances in fingerprint technology. 2nd ed. Boca Raton, London, New York, Washington, DC: CRC Press; 2001 chapter 3. 3. Theaker Brenden J, Hudson Katherine E, Rowell Frederick J. Doped hydrophobic silica nano- and micro-particles as novel agents for developing latent fingerprints. Forensic Sci Int 2008;174:26–34.
K. Singh et al. 4. Sodhi GS, Kaur J. Powder method for detecting latent fingerprints: a review. Forensic Sci Int 2001;120:172–6. 5. http://www.chemguide.co.uk/analysis/chromatography/thinlayer. html. 6. Bridges BC. Practical fingerprinting. New York: Funk & Wagnalls Publishing Company; 1963, p. 250–3. 7. Graham D. Some technical aspects of demonstration and visualization of fingerprints on human skin. J Forensic Sci 1969;14(1):1–12. 8. Goode GC, Morris JR, Margot Pierre, Stoilovic Milutin. A review of their origin, composition and methods of detection. Aldermaston: AWRE; 1983, Report No. O 22/83. 9. Bridges BC. Practical fingerprinting. New York: Funk and Wagnalls Company Inc.; 1963. 10. Sodhi GS, Kaur J. Novel, cost effective organic fingerprint powder based on phloxine B dye. Def Sci J 2000;50(2):213–5. 11. Kerr FM, Haque F, Barson IW. Organic based powders for latent fingerprint detection on smooth surfaces. Part I. Can Soc Forensic Sci Int 1983;16:39–44. 12. Sodhi GS, Kaur J, Garg RK. A fingerprint powder formulation based on rhodamine B. J Forensic Ident 2003;53(5):551–5. 13. Gabay Almog J. Chemical reagents for the development of latent fingerprints. III. Visualization of latent fingerprints by fluorescent reagents in vapor phase. J Forensic Sci 1980;25(2):408–10. 14. Sodhi GS, Kaur J. A novel, cost effective organic fingerprint powder based on fluorescent eosin yellow dye. Indian J Criminol 1999;27(3–4):73–4. 15. Howard S. Basic fuchsin – a guide to one step processing for black electrical tape. J Forensic Sci 1993;38(6):1391–403. 16. Sodhi GS, Kaur J, Garg RK. Fingerprint powder formulation based on basic fuchsin dye. J Forensic Med Toxicol 2004;21(1):8–9. 17. Garg RK, Kumari Harish, Kaur Ramanjit. A new technique for visualization of latent fingerprints on various substrates using powder from turmeric: a rhizomatous herbaceous plant (Curcuma longa). Egypt J Forensic Sci 2011;1:53–7. 18. http://www.freepatentsonline.com/4176205.html.
Please cite this article in press as: Singh K et al. Visualization of latent fingerprints using silica gel G: A new technique, Egypt J Forensic Sci (2012), http://dx.doi.org/10.1016/j.ejfs.2012.09.001