Forensic Document Examination Instruments and Equipment PDF

Instruments and Equipment in Forensic Document Examina Forensic document examiners need certain instruments and instruments and equipment used by forensic document examiners at that may not be visible to the naked eye. Below are some of the scientific equipment in examining documents and determining...

Instruments and Equipment in Forensic Document Examina Forensic document examiners need certain instruments and instruments and equipment used by forensic document examiners at that may not be visible to the naked eye. Below are some of the scientific equipment in examining documents and determining facts the PNP Crime Laboratory: 1\. Optical Aids A microscope is an optical instrument that consists of a combination of lenses that allows the user to view a magnified image of a small object (Brenner, 2004). The magnifying glass or hand lens is the simplest microscope. Light from the object is bent, or refracted, as it passes through the curved lens and into the eye, where it forms a magnified virtual image. The lens is usually mounted in a frame with a handle. Their magnification limit is about five to ten times the true size of the object (Tilstone, Savage, & Clark, 2006). A stereo or stereoscopic microscope is an instrument for blending into one image two pictures of an object from slightly different points of view so as to produce upon the eye the impression of relief and solidity and a three-dimensional viewing (Brenner, 2004). Stereoscopic Microscope. The stereoscopic microscope is the most important and the commonly used equipment in forensic document examination. Stereoscopic microscopes offer between 10 and 50 power that includes both incident and transmitted illumination, Power refers to the amount of magnification the microscope provides (2 power provides 200% enlargement). This type of microscope a magnified three-dimensional image that assists the viewer in the study of pressure patterns, crossed lines, TOOLS, TECHNIQUES AND PROCED lems non- ding iner Some examinations also require special lighting effects. Transmitted light is light that is passed through a transparent or translucent medium (Brenner, 2004). It is used in the examination of documents to determine the presence of erasures, matching of serration, and some other types of alteration. ring cise mal Ten wn 5\. Specialized Equipment Forensic document examiners use additional equipment Transmitted Light based on and eed fa the for a The pe nt se he of by specialized needs interests crucial to solving certain cases. When documents are illuminated by ultraviolet light, certain inks and papers will glow, making them visible to the naked eye in an otherwise darkened room. The ultraviolet light machine is used to detect mechanical and chemical erasures, which certainly change the reflectivity and fluorescence of the affected area. The exposure of Ultraviolet Light Machine the document to ultraviolet light is useful when it consists of several pages and substitution is suspected. This machine is also used in the examination of counterfeit bills. Genuine bills have distinct features like the serial number, security fibers, fluorescent printing, special paper and other features that react and flourish when subjected to ultraviolet light, A comparator is a device for comparing a measurable property or thing with a reference or standard. A video spectral comparator(Fig. 5-10) consists of a camera, a video \*FORENSIC EXAMINATION OF QUESTIONED DOCUMENTS images from 24 to 48 times. Signatures and handwritings can also be photographed for larger and clearer images. 58 FORENSIC EXAMIN can be compa different. Photogra can be clas characteristi be compared vision. 6\. Portable Equipment Microfiche Machine Document examiners also need portable equipment such as a transportable microscope or the portable VSC-4CX because some documents cannot be released for examination and must be examined at their location. For example, they can be taken to courthouses to view wills or police stations to look at documents they do not want to release. A portable luggage carrier also enables a document examiner to carry equipment easily (Koppenhaver, 2007). 7\. Protective Equipment also all Forensic document examiners equipment like cotton gloves to handle original documents in cases in which fingerprints may be an issue. A fireproof safe or use protective file box is also useful to store and protect original documents from harm. 3\. To prepare While every deta court dem no bearin appropria backgrou across th Phot a magni demonst the know to be co shown i or differ Ph and afte electron togethe oblitera radiate 52 FORENSIC EXAMINATION OF QUESTIONED DOCUMENTS erasures, indentations, writing over folds, and similar problems (Koppenhaver, 2007). Other optical aids include other good quality, non- distorting magnifiers in various strengths like strong reading glasses and optivisors that can be worn so that the examiner can view documents while leaving both hands free. 2\. Measuring Devices Rulers, gauges, grids and other accurate measuring devices are important for document examiners to obtain precise measurements. The typewriting test plate is used to detect any abnormal horizontal or vertical alignment of typewritten characters. Ten characters per inch (cpi) is called pica and twelve cpi are known as elite. Placed over the typewritten page, these gauges need to be accurate to ensure a more comprehensive analysis of a variety of situations. The printed image is on the bottom of the clear plastic plate, which eliminates shadows and allows for direct photography. The protractor measures angles and is also called a handwriting slope instrument. Other test plates include the letter slant or handwriting comparison test plate and the type angle measurement. 3\. Duplicating Devices Forensic document examiners need camera equipment for clear close-up photographs of original documents. These photographs are useful in studying documents in place of the original and in enabling a jury to see the characteristics of writing and the reasons for conclusions more clearly than by looking at the original documents. 4\. Proper Lighting In addition to daylight, various types and intensity of lighting fixtures is crucial for critical examinations in a document laboratory. Different types of lights can reveal subtle details essential for revealing flaws and stains on documents. Some exa special ligh Trans is passed or translu 2004).It is of docume presence o serration, a alteration. 5\. Specialized Forens examiners equipment specialized interests c certain cas When illuminated light, cert papers wil them visibl eye in darkened ultraviolet used to det and chem which the cer refl fluorescenc The area. the docume several pag also used in have distin fluorescent and flourish A com property of spectral co \*FORENSIC EXAMINATION OF QUESTIONED DOCUMENTS images from 24 to 48 times. Signatures and handwritings can also be photographed for larger and clearer images. 58 FORENSIC EXAMIN can be compa different. Photogra can be clas characteristi be compared vision. 6\. Portable Equipment Microfiche Machine Document examiners also need portable equipment such as a transportable microscope or the portable VSC-4CX because some documents cannot be released for examination and must be examined at their location. For example, they can be taken to courthouses to view wills or police stations to look at documents they do not want to release. A portable luggage carrier also enables a document examiner to carry equipment easily (Koppenhaver, 2007). 7\. Protective Equipment also all Forensic document examiners equipment like cotton gloves to handle original documents in cases in which fingerprints may be an issue. A fireproof safe or use protective file box is also useful to store and protect original documents from harm. 3\. To prepare While every deta court dem no bearin appropria backgrou across th Phot a magni demonst the know to be co shown i or differ Ph and afte electron togethe oblitera radiate A 62 FORENSIC EXAMINATION OF QUESTIONED DOCUMENTS During the first century, the Chinese began making paper from the inner bark of bamboo and hemp. The Arabs learned this when they conquered the Chinese in 751. In 1960 William Rittenhouse of Roxborough, Philadelphia founded the first paper plant in America. Types of Paper Papermaking has become a scientific process using high sophisticated equipment. Most paper today is made from wood p and may contain some cotton, and many other different types an manufactured for a variety of uses, as enumerated below (Koppenhave 2007). 1\. Newsprint pu the least expensive paper manufactured; composed mostly of ground wood, causing it to discolor easily; high opacity is a result of the impurities of the wood 2\. Offset - uncoated paper that usually contains fillers and additives; bleached and sized to resist water; more expensive than newsprint; used for the publication of books, catalog sheets, loose-leaf inserts and tablet paper 3\. Bond paper - originally used to print stocks and bonds; popular in the modern business office; the higher the rag content, the more expensive the paper \- 4\. Lightweight, uncoated paper example is the onionskin, which comes in smooth or cockle finishes, and snap-out forms, which are frequently made with manifold papers made from wood fibers; another example is \"bible\" paper 5. Specialty paper includes carbonless paper, which is coated on both sides to transfer data from one page to another; contains special finishes that must come in contact with each other to transfer the writing or typing to the subsequent page 6\. Gummed papers - used primarily for labels; curl-proof 7\. Text paper - the most expensive, uncoated paper because of its superior grade; comes in antique, vellum, or smooth finishes; used for promotion pieces, announcements, invitations, greeting cards 8. Coa som prin 9\. Bri us 10\. Kr st CC 11\. T 12. fi Sa develop the wo to the moder A design Prop prop (Kop 1 DE VOLLMUNDIGES AUSGEWOGENER MIT GOLD GEROSTETE. aper ned hia highly d pulp es are haver, d; Dr d d e go WRITING MATERIALS, TOOLS AND EQUIPMENT goes through several layers of coating, some of which are dull-coated to cut down the glare; used 8\. Coated paper primarily in textbook publications 9\. Bristol- used to make index cards and tag paper, which is used for file folders; strength is its most important feature 10. Kraft paper - coarse, unbleached, heavy paper; noted for strength; used for paper bags, package wrapping, and corrugated boxes new kind of paper strengthened with plastic filaments; repels most ink; principally used in the 11\. Tyvek manufacture of large mailing envelopes 12\. Safety paper \- designed to reveal alterations; used principally for checks 63 Safety papers are printed with fugitive inks (or invisible inks) that develop a strong color when treated with ink eradicator. For example, the word \"VOID\" appears when ink eradication solutions are applied to the paper. The word \"VOID\" also appears in photocopies of some modern safety papers. Another security feature of safety paper are invisible fluorescent designs that can only be revealed through fluorescent light. Properties of Paper M Another factor for consideration in examining documents is the property of the paper, which helps determine how the paper is used (Koppenhaver, 2007). 1\. Weight Papers are weighed by the ream. Letterhead stationery is usually 25 pounds per ream. 2\. Strength - Paper is categorized by its strength. Strength is measured as tensile strength (or the amount of force parallel to the plane of the specimen required to produce failure) and as tear strength (or the internal tearing resistance). Tensile strength is used to determine the durability of paper. Bursting tests and puncture tests are used to measure paper strength. 3\. Corrugation Corrugated paper is used when tensile strength becomes an important factor. Cardboard boxes