{"id":264,"date":"2022-01-24T11:35:36","date_gmt":"2022-01-24T11:35:36","guid":{"rendered":"https:\/\/ebooks.inflibnet.ac.in\/antp07\/?post_type=chapter&p=264"},"modified":"2022-01-24T12:25:14","modified_gmt":"2022-01-24T12:25:14","slug":"264","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/antp07\/chapter\/264\/","title":{"rendered":"Classification for Filing Fingerprints"},"content":{"raw":"
\"epgp<\/a>\r\n<\/span><\/div>\r\n \r\n\r\n \r\n\r\n1.\u00a0 Introduction:<\/strong>\r\n\r\n \r\n

The primary objective of classification of fingerprints is to devise the formula by which a given set of fingerprints can be traced and recorded. Each individual possess unique fingerprints and we have a large population. So, in order to match a fingerprint from crime scene to the recorded fingerprints in the bureau, a method for filing fingerprints is necessary to efficiently match in appropriate time. As it is really a time consuming process to match each and every recorded fingerprint, a proper method of classification of fingerprint for searching purpose is needed. Before classification of fingerprint, it is necessary to know about fingerprints.<\/p>\r\n \r\n

F<\/em>ingerprints <\/em>can be defined as the prints or impression of the fingers on any material like paper, glass, or clothes. There are three fundamental principles of fingerprints: F<\/em>i<\/em>rs<\/em>t<\/em>, Fingerprints are individual characteristics and no two people can have exactly the same pattern of fingerprints even the monozygotic twins have different fingerprints. This is the first fundamental principle of fingerprints. Second<\/em>, principle says that a fingerprint does not change throughout the lifetime of an individual and this is the reason behind its world wide application in identification of individuals. Third<\/em>, fundamental principle again refines its application in identification by stating that fingerprints have ridge patterns which can be classified. Fingerprints are categorized on the basis of presence or absence of patterns such as whorls, loops and arches.<\/p>\r\n\"\"<\/a>\r\n

F<\/em>ingerprint fixed points: <\/em>These are the points by which a particular pattern can be identified. These are point of core and the triradial point. Point of core can be referred to as the landmark of ridge counting. Triradial point provides the landmark for ridge tracing and thus provides the outer border of pattern area.<\/p>\r\n\"\"<\/a>\r\n

R<\/em>idge patterns: <\/em>There are three basic types of patterns in fingerprints \u2013 Arches, loops and Whorls. These basic patterns are again subdivided on the basis of complexity of the ridges. Thus Arches can be \u2013 Plain Arch or tented arch; Loops can be divided into Ulnar loop and radial loops; Whorls can be divided into plain whorl or composites which include central pocket, lateral pocket, twinned loop or accidentals.<\/p>\r\n\"\"<\/a>\r\n\r\n2. Classification for filing finger prints:<\/strong>\r\n

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Fingerprint classification system permits the retrieval of the paper records of concerned person from large databases of fingerprints in just a few minutes or it may help in the identification of matches between one to many search. Fingerprint classification is thus partitioning of large domain search into small subsets based on the type of query. It is widely used in criminal investigation sectors. Classification of fingerprints is done by assigning numerical values like alphabetical order is followed in dictionary to arrange words for the ease of search. The well known method of classification is known as \u2018<\/em>Henry system of classification\u2019 <\/em>which is universal in its use, named after its originator Sir Edward Richard Henry.<\/p>\r\n \r\n\r\n3.\u00a0 Henry system of classification<\/strong>\r\n\r\n<\/div>\r\n \r\n\r\n3.1 <\/em><\/strong>P<\/strong>r<\/strong>imary classification:<\/strong>\r\n\r\n \r\n

Primary classification is derived taking into account the fact that arches occur 5 percent, loops 60 percent and whorls and composites being 35 percent of the impressions, therefore, in primary classification arches are included under loops and composites under whorls. Thus, a finger can possess either a loop or a whorl in primary classification.<\/p>\r\n \r\n\r\n3.1.1\u00a0 Method:<\/strong>\r\n\r\n \r\n

The technique involved in taking fingerprints for classification purpose is as follows: In a slip, the rolled impression of the fingers of right hand is recorded in line in the order of thumb, index, middle, ring and little finger. Immediately below them, impressions of the fingers of left hand in the same order are recorded. Then at the bottom of the slip, plain impressions of index, middle and ring fingers of both hands are also recorded. For correct classification, it is essential that the fingers should be printed in correct sequence.<\/p>\r\n\"\"<\/a>\r\n\r\n3.1.<\/em>2 Symbols:<\/strong>\r\n\r\n \r\n

Before classification, the symbols for the patterns are marked below the patterns in the fingerprint slip and each pattern is assigned a numerical value. Thus Henry system of classification is divided into two classes: Those which have numerical values, and those which do not have numerical values.<\/p>\r\n\"\"<\/a>\r\n\r\nThus patterns having numerical values are whorls and composites whereas arches and loops have no numerical values.\r\n

\r\n\r\n \r\n\r\n3.1.3 Numerical values:<\/em><\/strong>\r\n\r\n \r\n

As the impressions are read off in pairs, numerical values are assigned by pairing of fingers. Thus f<\/strong>i<\/strong>ve pairs <\/strong>are formed as right thumb and right index; right middle and right ring; right little finger and left thumb; left index and left middle; left ring and left little finger.<\/p>\r\n \r\n\r\n\"\"<\/a>\r\n

The arrangement possible in first pair are: right thumb a whorl, right index a loop; right thumb a loop, right index a whorl; both right thumb and right index have loop; both have whorl. Possible arrangements of the first pair with symbols are set out \u2013 the numerator letter refers to the first of the pair and the denominator letter refer to the second of the pair.<\/p>\r\n\r\n<\/div>\r\n\"\"<\/a><\/em>\r\n

The same number of combination for second pair, i.e. 4 and when each of these compared with the combination of first pair then the total combination of the two pair becomes 16 (4 X 4). Likewise the third pair has 4 arrangements when compared with preceding two pairs, number of combination becomes 64, compared with fourth pair, combination raised to 256, and with the fifth pair, it becomes 1024. The number 1024 is the square of 32 thus a cabinet containing 32 sets of 32 holes arranged horizontally would provide locations for all combinations of loops and whorls taken in pair. Now, a whorl will be assigned a numerical value of 16 if occurs in the first pair; in the second pair, it assigned a value 8; in the third 4; in the fourth 2 and in the fifth 1. Loops do not possess any numerical value and therefore denoted as 0.<\/p>\r\n\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\r\n\r\n3.1.4\u00a0 \u00a0<\/em>Classification:<\/strong>\r\n\r\n \r\n

Classification involves adding the numerical values separately of all the patterns present in numerator and denominator. Then a unit value is added to both the numerator and denominator. This is done to record the file of a person who has loop patterns in all the ten fingers.<\/p>\r\nConsider a pattern\r\n\r\n\"\"<\/a>\"\"<\/a>\r\n\r\n3.2\u00a0\u00a0 <\/em>Secondary classification:<\/strong>\r\n\r\n \r\n

The system can be further modified in case of large accumulations to make the filing and search easier as well as quicker by introducing secondary classification. Only the fingerprints of index finger are considered in secondary classification. Numerator denoting the symbol of right index finger whereas denominator, the symbol of left index finger. Thus the index finger of each hand is taken as f<\/em>ulcrum <\/em>and capital letter is used to denote its pattern symbol. Symbol of the thumb in small letter is placed to the left of the f<\/em>ulcrum <\/em>and symbol of the remaining fingers in small letter to the right of the f<\/em>ulcrum. <\/em>In secondary classification, infrequently occurred patterns are utilized such as arches, tented arches and radial loops. Formula indicates that the slip containing the impression will be found under classification number , and it will be included in the collection specialized by having a tented arch in right thumb, an arch in the right index and a radial loop in one of the remaining fingers of the right hand while in the left hand there is a arch in left thumb; radial loops in both left index and one of the remaining finger.<\/p>\r\n \r\n\r\n \r\n\r\n3.3 <\/em>Sub-classification or sub- secondary :<\/em><\/strong>\r\n\r\n \r\n\r\n3.3.1 <\/em><\/strong>B<\/strong>y Arches and Loops<\/strong>\r\n\r\n \r\n

In primary classification, we have distinguished between loops and whorls and loops arches, tented arches, radial and ulnar loops. So now we are about to distinguish them into subclasses and groups.<\/p>\r\n \r\n

In \u00a0index \u00a0finger \u00a0arches, \u00a0radial \u00a0and \u00a0ulnar \u00a0loop \u00a0can \u00a0occur \u00a0in \u00a0possible \u00a0nine \u00a0combinations \u00a0for \u00a0the formulation of nine subclasses as depicted<\/p>\r\n\"\"<\/a>\r\n

The letters arranged horizontally refer to the right, those vertically to the left index finger. Thus under subclass will found the slips with an arch in both index finger, under ,those with an radial loop in right and arch in the left index finger.<\/p>\r\n \r\n

I<\/strong>n subclass , <\/strong>Arches may occur in 1(thumb), 2(index), 3(middle), 4(ring), or 5(little) fingers in right as well as in left hand. The possible arrangements of groups are 16 as depicted below for one hand. So, the total number of groups created by utilizing them will be 16 X 16 = 256.<\/p>\r\n\"\"<\/a>\r\n

Likewise, in subclass ; in subclass ; in subclass <\/strong>; 256 such groups can be made. However, in practice a smaller number is employed which is formed by deciding whether there are one, two or three Arches to the right of the index finger or fulcrum. These groups are denoted as depicted in figure- 4 as A; aA; Aa; aAa; A2a; aA2a; A3a; aA3a; they are arranged amongst themselves in this sequence. So, the possible arrangements are reduced to 8 instead of 16 and hence, 64 possible groups instead of 256 when considering both the hands.<\/p>\r\n\r\n

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