INTRODUCTION:

The Scientific field is advancing and hence the techniques for tampering of Documents are also enhancing in order to have a maximum destruction so that the evidential data is lost as well as to obstruct proper investigation. The culprits or the forgers are using several physical and chemical Method for the destruction of the documents. The most common types of cases encountered by the investigators are of Alterations, Additions, Erasures, Obliteration, invisible writings and charred documents.

Till now several instrumental analysis techniques have been developed for the decipherment of the data from the destroyed Questioned document. But commonly encountered one’s for the destruction of documents is by burning them, which are also known as Charred documents. The decipherment of the data is quite difficult from the charred documents so the methods need to be developed. Even though the forger’s, terrorist are making the use of chemicals , juices and extracts from the natural sources like plants in order to create invisible writings possessing secret codes and information, and an expertise is required to them. Culprits are making addition and alterations in the questioned documents with an attempt to do forgery and fraud. So, the methods and techniques needs to be developed for their decipherment followed by ascertaining the pre-eminent method. This paper will summarize the most relevant available methods for the detection and decipherment of tampered documents developed during the past fifty (50) years and will also focus on the areas of deprivation.^[1][2][3][4]

Erasures:

In depth research has been done on the erasure and their decipherment by Osborn.^[5] In his book he has mentioned about the different methods for the detection and decipherment of erasures which includes lightning techniques such as oblique, transmitted, IR, UV etc followed by various types of physical and chemical methods used in analysis.

Pencil erasure is not an easy task. Different individuals prefer different types of erasers for the concealing of the written material such as emery paper eraser, fibre glass eraser etc. Even though people also use some chemicals such as hydrogen peroxide which seems to produce some positive effects by breaking the bonds between the paper and the pencil graphite (making it loose).^[5]The soft rubber and the abrasive erasers have been compared and is found that soft rubber disturbs the paper surface less and cannot be deciphered easily. The study reveals that microscopic study help in the detection and decipherment of the erasers but the specific microscope and the extent of decipherment is not explored yet.

Different techniques have been devised for the detection of erased pencil writing which includes the visual examination under the daylight and dark conditions. Earlier performed experiments show that the day bright light interfere with the detection therefore it is recommended to examine the tampered document with transmitted light. The Research has a gap that fails to explain the other sources of light with their extent and limitations of decipherment. Dr. Harrison has reported that the decipherment of erasure can be done by placing cleaned, well polished silver nearby to the suspected point of eraser. If tarnishing of the silver is seen it means there is rubber residue. And there is no other method that can reveal the erasures. ^[6]But it is not always so, because silver may also tarnish in the absence of water or oxygen or at low level of ozone. The factors controlling tarnishing of the silver has not been quoted in the previous studies.

S.S. Kind and M.D.G Dabbs in 1979 have worked on detection of “India rubber” erasure on the paper by using Lycode powder. Lycode powder is prepared by dyeing the Lycopodium spores with some basic dyes .The structure of the spores is tetrahedral which provides it a capability of being used as thief powders and tagging powders. The erasure was performed on cards and papers (Newspapers and Xerox papers) using a variety of rubbers. The results were best seen in the documents which were recently erased. Therefore it failed to give good results in case of documents which were not recently erased and time lapsed in their examination. The reason behind diminution of the results was not clear .It was assumed that the grease and oil from the eraser that soak into the porous surface of the newspaper.^[2][7]Later on the method was implemented by using nine different types of inks and removing the ink marks by chemical means and the result were negative, no lycode powder adhesion took place. The experiment was carried out in order to find out the principle behind the Lycode powder adherence to the paper surface. Researchers found that the rubber erasure produces more intense stains of lycode powder as compared to plastic erasure. They also reported that the effect of powder adhesion will reduce if the hands are washed immediately beforehand. An experiment was performed by washing few silver of the pencil with dichloromethane followed by Lycode powder application. Positive results developed. Later on different types of pencil erasers were taken and the experiment was performed on metal and glass surface. Similar results were obtained. It was concluded that the repeated use of lycode powder can be done on the questioned document and can be easily wiped off using a tissue paper. The adhesion of the lycode powder is because of the greasy and oily substances on the surface of paper, metal or glass. The technique was easy and non destructible but the results were not constant.^[2][7][8]The mechanism of lycode powder proved beneficial in the detection of a suspected altered receipt by J.R Welch (1982). Various illumination techniques such as Infrared, UV luminescence failed to detect the indentations on the receipt. The purple lycode powder (NL 107) was sprinkled over the fainted areas of indentations were detected. The patterns of adherence helped in identifying the individual eraser strokes.^[2][9]

Later on Red Lycode powder (NL. 104) was used and similar patterns were obtained. But the drawback of this method was that the process of colour development was slow hence time consuming so there is a need for the development of such chemical treatment methods which are quick and accurate. A lot or research has been done in this area but still the major forms of erasures has not been explored much as a result of which there comes a need for the development of some techniques.

Charred Document:

The real picture on the problems faced by the investigators in the handling and treatment of charred documents is described in journal titled Charred Documents, their handling and decipherement. The handling of the charred documents requires utmost care as the burnt document is extremely fragile. Advancement in the field of charred document analysis took place during World War II .Due to the scientific skills used by the pioneers at that time it is possible to decipher the original contents from the burnt document. Generally the charred documents are found in the place of safe keeping in strong boxes but the documents which are burned at a fireplace, stove and open area requires decipherement.^[3]

David A. Black (1948) transported the two safe boxes containing charred documents from Philippine Republic by packing the safe box and the documents by cotton wool. ^[1]He stated that the charred material should be removed as a mass rather being removed separately by sliding a thin metal or pie tin below the charred document and gently withdrawing it. Flat bladed tweezers are also available which can be used for the handling of charred documents by avoiding the air interference. Theories have been given for separating the burnt document by soaking it in hot water dilute glycerine water bath and alcohol wash.^[10]

Tyrrell (1939) also examined a case of charred document in which the bonds were tied with a string which in turn produced deep wrinkles at the places where string was present. A blade of pocket knife, pair of fine pliers with curved nippers was used. ^[4]Black also used 18x20 ferro plates in order to provide support to the charred documents and there after storing the charred documents undisturbed in a rack and then further examination was performed.^[1]

The work carried out by Gross included the reconstruction of the burnt documents by softening the fragments of charred documents in water, steam because of the phenomenon that burnt documents are hygroscopic. But extra care should be taken while treating the documents with water as they might get saturated and sink to the bottom of the tray .Lastly the drying process includes the usage of gum Arabic or celluloid- acetone type. Another variation for this examination was also given by placing the charred document over the gummed surface and then placing the cloth piece folds over it without touching the burnt document surface. It was found that the burnt document becomes soft and flexible but not applicable in every case. Therefore some advanced methods need to be devised which can be beneficial in charred documents handling as they are highly fragile.^[11]

The Decipherment procedures were developed for the detection and decipherment of charred documents. The photographic method included:

Contact process:

The experiment was performed by Davis (1922) from Bureau of Standards. Who concluded that the recently burnt documents emit some gases and latent image can be recorded. He also stated that the writing instrument either pen, pencil etc upon the paper before burning inhibit the escape of gases and the emulsion remain unfogged in that specific areas.^[12] Further experiments involved the treatment of charred document with commercially colour blind photographic sheets in red lights and pouring the emulsion from the side opposite to the burnt area. Later on processing them by Eastman D11 and filtered UV light before processing and found that the results were much better than the results obtained without treating with UV.^[1]Whether this technique will give positive results in the case of “Old burnt documents” is still questionable.

Filter Photography:

The filter create a contrast difference between the background and the areas of ink deposition of burnt paper. Different types of filters are used such as Wratten #48 deep blue in combination with commercial film for the detection of charred documents but the literature does not consider different colour of inks and the degree of decipherment with the help of filters.^[3]

Infrared Photography:

This technique is not that much successful in deciphering the data from charred documents. This technique uses Wratten #87 filter (Infrared) in combination with Eastmen Infrared plates and processed by Eastmen DK 50 developer developed by Dr. Bendikson (1936). For better results infrared illumination is given for a longer period of time (1.30 minutes) at a focal length of 1.6 with filter paper #2 two photofloods placed at a distance of 3 feet from the document It may also produce remarkable results in case of typewriting, pencil or dense iron ink.^[3]

The Visual methods of decipherment involved:

Reflectivity Method:

The burnt documents are viewed at different angles using a control source of light. The technique of oblique lightning and direct lightning is performed. Results success depend upon the density of the ink deposited and the degree of charring of the document. Effective way of treating charred documents by oblique light is achieved by placing the burnt document between two clear glass plates and in case of reflectivity technique the document is placed on a single sheet of glass with making use of transparent tape. The document glass is then positioned such in front of the camera that the illumination from filter paper #2 photoflood which placed underneath the camera lens creates a distinct.^[3]

Alcohol-Glycerin Immersion Method:

It is a simple, fast and non destructive method. During the Era when American forces recaptured manila, a method of treating the charred documents with glycerin- alcohol water was devised. The composition contains- 2 parts of water, 5 parts alcohol, 3 parts glycerine.The success rate for deciphering by this technique was 90%. The readings were taking under following conditions:- i) Before immersion ii) During immersion iii) Completely immersed iv) Dripping wet and v) After Blotting. Each component used in this method has significance; alcohol act as wetting agent whereas glycerine helps in partial drying of the burnt document by restoring some part of water before and after drying. ^[1]

Silver Nitrate Method:

The working principle depends upon the reduction of silver nitrate by the iron by products of the burning process. Superintendent Cherrill (1941) discovered the method by placing the burnt paper on glass plate and treating the sample with 5% of Silver nitrate aqueous solution and then placing the second glass plate over the document, the image gets developed as a black image against the background. The weaker concentration of the silver nitrate solution is generally recommended in the case of fainted original writings. The permanent record of the written material can be taken by washing the treated burnt document with water and then drying it rapidly.The main consideration for the success of this method will depend upon the storage of documents in darker area ie. away from sunlight.^[3]

Chloral hydrate Method:

Solution of 25% chloral hydrate in alcohol for the treatment of the charred documents is used. The burnt document can be either treated by immersing it in the prepared solution of chloral hydrate or by using the camel brush. ^[13]The chloral hydrate shows a clarifying action by depositing over the areas of figures, words in the form of crystals. The temperature plays a vital role in this method. The optimum temperature required is 60 degree. So this method will fail to develop the result if the required temperature is not achieved. Aniline inks which are washable does not show good results with chloral hydrate treatment whereas printing inks ,typewriting inks and iron gall ink show tremendous results.^[3]According to a report given by Grant (1941) proposed that test depends upon the incomplete combustion of the cellulose and that normal papers show poor results as compared to heavy loaded papers.^[13]

Potassium Ferro cyanide:

Application with Hydrochloric acid produced blue colour when coming in contact with the iron component of the ink with a theory that even if the paper is burned then also there are remnants of iron embedded into the paper. But later on this application was used in the burned case analysis and the results were disappointing as colour did not turn to blue it changed to pink and the cause of this was unknown whether the result did not appear because of iron residue not remaining in the paper after burning or other factor.^[12]

Later on Lightning techniques were also implemented such as UV by layering the burnt document with pale mineral oil and petroleum spirits in order to create fluorescence. The phenomenon was that the ink absorbed more oil as compared to the background and creates a difference in the two areas hence fluorescence. This technique was successful only on printed, type written documents and carbon copy but they failed to give results with the ordinary pen .^[14]

Invisible Writings:

The culprits are using different natural and synthetic sources which are fulfilling the need of creating invisible writing. There are various types of invisible inks available in the market. The most common one’s are the disappearing ink, vanishing ink and erasable which is used in the field of textile, paint and other chemical industries hence easily available for the fraudulent purposes. These inks work on the principle of Acid /base chemistry.^[15] Thymolphthalein is a substance, below the PH 9.3 it is colorless and above PH 10.3 it is blue. Majority of the invisible inks are based upon this acid base (PH) indicator. ^[16].The forensic examiners are encountering the cases of invisible writings in various fraudulent cases. So, there is an urgent need for the development of scientific methods. A study has been performed using three different types of papers bank cheques, standard ruled white foolscap paper and a plain A4 paper in deciphering vanishing and erasable inks.^{[17][18][19][20]}

The optical deciphering was done using magnifying lens with different light sources, UV & IR illumination (VSC 6000) and the chemical deciphering was done using Sodium Hydroxide solution different concentrations. Traditional methods failed to detect invisible inks whereas the erasable inks were seen as faint red lines under low IR wavelengths. The results showed that paper 2 and 3 had dramatic deterioration of visibility after 40 hrs whereas paper 1 after 2 hrs. On applying various concentrations of solutions of NaoH it was found that with increasing the concentration of solution the time period for ink stability was increased without any damage to the paper and the Bank check was found to be the most resistant paper for the analysis.^{[17][18][19][20]}

CONCLUSION:

The techniques for the detection and decipherment of various forms of tampered documents have been developed during the ancient times mainly during the time of II World War. There are several physical and chemical means of detecting and treating different forms of tampered documents but the factors that control their working needs to be considered .There are limitations of each technique therefore a need to differentiate and categorize the most feasible and least effective technique for the detection and decipherment should be done. Charred documents being the most fragile type of tampered document should be given extra care during the handling process. With the growing technology there is a need to study different types of inks and their composition and checking the extent of decipherment by the existing methods of analysis. The selective techniques for analysis and examination of tampered document must have qualities like cheap ,easy to use, easily available, good accuracy and do not damage the document. Hence there is an urgent need to develop selective scientific techniques and methods for the detection and decipherment of tampered documents which occupies the major areas in questioned documents so that the investigators can reveal facts and findings in the cases more accurately and in a speedy manner with a less chance of errors so as to avoid the damage of the questioned document.

REFERENCES:

1. Doud, D. Decipherment of charred documents. Journal of Criminal Law and Criminology. 38(5); 1948: Jan-Feb.

2. Kind, S.S., Dabbs, M.D.G. Use of Lycode powder in detection of Erasure. Journal of forensic Science Society.9; 1979: 175-17. Available from: URL: http://dx.doi.org/10.1016/S0015-7368 (91)73120-4 .

3. Doud, D. Charred Documents, their Handling and Decipherment: A summary of available Methods for treating Burnt Papers, Journal of Criminal Law and Criminology. 43(6); 1943, Article 13.

4. Tyrrell, F John. Decipherment of charred Documents, Journal of Criminal Law and Criminology. 30(2); 1939-1940: 1-10.

5. Osborn, AS. Questioned Documents. Boyd Printing Co., New York.1929.

6. Wilson R. Harrison. Suspect documents, their Scientific Examination, Frederick A. Praeger Publishers, New York,103.

7. Kind, S.S., Watson, M., Bland, H.H. and Smith, G.B. The International Microform Journal of Legal Medicine. 8 (2);1973:56.

8. Kind, S.S. 1973, British Patent 1399551. Available from: URL: http://dx.doi.org/10.1016/S0015-7368(79)71270-9.

9. J.R Welch. Lycode powder in case of Erasure. Journal of Forensic Science Society. 22(1); 1982: 43-44 . Available from: URL: http://dx.doi.org/10.1016/S0015-7368 (82)71443-4.

10. A Practical Textbook for Magistrates, Police Officers and Lawyers 5th Edition.

11. Mitchell, C. Ainsworth. Documents and their scientific examination: with especial reference to the chemistry involved in cases of suspected forgery, investigation of disputed documents, handwriting, etc. Charles Griffin, London. 1922: pp 83.Available from: URL: https://archive.org/details/cu31924032589313.

12. Gross, H. Preserving and Deciphering Burnt Paper, Criminal Investigation A Practical Textbook for Magistrates, Police Officers and Lawyers. 1906; 5th Edition.

13. Davis,” Scientific papers of the bureau of standards” No.454, issued October18, 1922 by U.S Government Printing office.

14. A New Method for the Decipherment of Charred Documents. Nature (London) Abstracts in Scientific American, December.1941:340.

15. J. Grant, Analyst. Decipherment of Charred Documents, Some Recent Work and a New Method. 67; 1941:42-47.Available from: URL: http://dx.doi.org/10.1080/00085030.1968.10757261.

16. Bramley Cs. Akzo nobel decorative coatings Ltd., Applicant. Color changing paint. European Patent 2004;1:400:574A1

17. Dawson, GA. Fradulent use of vanishing inks, paper presented at the Meeting of The American Society of Questioned Document Examiners. BC: Vancouver.1980.

18. Emily W. Faded handwriting Forensic Document Examiner. 2009.

19. Basalaha, RF. Vanishing inks. In Limits of scientific proof in cases of counterfeiting and forgery. Edited by Basalaha, RF .Dar Nobar Printing, Egypt. 1906;1^st edition: pp318.

20. Krup RD. DAP Products Inc., assignee. Ready to use Spackled repair product containing dryness.US Patent 2003; 6:351-528B1.

21. Throckmorton, GJ. Erasable Ink its ease of eras ability and its permanence. Journal of forensic Science.30; 1985:526.

22. Manal Abd-ElAzizi Abd-ElZaher. Different types of inks having certain medicolegal importance: Deciphering the faded and physically erased handwriting .Egyptian Journal of Forensic Sciences.4; 2014:39-44. Available from: URL:http://dx.doi.org/10.1016/j.ejfs.2013.09.002.

Received on 24.06.2017 Modified on 17.07.2017

Research J. Pharm. and Tech 2017; 10(11): 4085-4089.

DOI: 10.5958/0974-360X.2017.00740.5