The complexion may be fair, wheat coloured, dark, brown or shallow. The colour of an individual ranges from one area to another and depends upon race, patterns and weather conditions. The details
of the features regarding the eyes, nose, ears, lips, chin and teeth should always be carefully noted. The colour of irises, size of ear lobule should be noted. In certain individuals, lips may be thin or thick. The chin may be round, square, protruding or double (due to excessive fat). Expression of an individual changes after death.
Hair
Hair plays an important role in establishing identity as it resists putrefaction for a longer time. The hair of Indians is generally dark and fine, that of Chinese and Japanese is dark and coarse, while that of Negroes is curly and wooly. Some people in order to disguise their identity, might colour hair with henna, dyes or cosmetics. The hair may change colour in individuals working in certain trades like copper melters and indigo workers. To find out the chemical use of dyeing, a few strands of hair should be removed and they should be diluted in hydrochloric or nitric acid to dissolve the matter and then appropriate test should be done.
Medico-legal Importance of Hair
Hair is important in a crime investigation, as it sometimes remains on the body of the victim or on the alleged weapon. In rape and sodomy, pubic hair of the accused may be found on the victim or vice versa. Stains on the hair may sometimes indicate the nature of assault, for example, seminal stains in sexual offenses and salivary stains in asphyxial deaths. In chronic poisoning of heavy metals, the metal can be detected in the hair even after a long time. Singeing of the hair indicates burning.
Anthropometry
This system is used primarily for the identification of veteran criminals. It is also called Bertillon
Identification 19
system. It is applicable only to adults, as it is based on the principle that after 21 years of age no change occurs in the dimensions of the skeleton and ratio of the size of different parts to one another remains constant. Usual parameters which are taken are height of the person while standing, length of the head, width of the head, length of the right ear, width of the right ear, length of out-stretched arms, height of the trunk while sitting, length of the left foot, length of the left middle finger, length of the left little finger and length of the left forearm and hand. These measurements are recorded and kept. Certain peculiarities like the colour of irises or scars are also mentioned in the record. This system requires the employment of special instruments and large number of staff. This system has now been replaced by a better system called dactylography.
Dactylography
This is also known as the fingerprint system and consists of taking the impression of the pulp of the fingers and thumbs with printer’s ink on an unglazed white paper. It is seen that individual peculiarities of the pattern formed by the arrangement and distribution of the papillary or epidermal ridges on the finger tips are absolutely constant and persist throughout life (from infancy to old age) and, that patterns of no two hands resemble each other. The fingerprints of even identical twins are different. The chances of two persons having identical fingerprints is about one in thirty times the population of the world.
This system was first used in India in 1858 by Sir William Herschel but it was Sir Francis Galton who established it. Fingerprints are classified in four groups, namely, loops (about 67 per cent), whorls (about 25 per cent), arches (about 6–7 per cent) and composite form (about 1–2 per cent). They are further classified into subgroups since arches can be plain or tented; loops can be radical or ulnar; and composite can be central pocket loops, twinned loops, later pocket loops and accidental (Fig. 3.3).
(b) (a)
(d) (c)
Fig. 3.3 Various types of fingerprints: (a) arch, (b) loop, (c) whorl, and (d) composite. Poroscopy
It is a further modification of fingerprints, made by Locard. The ridges on fingers and hands are constituted of microscopic pores formed by openings of ducts of sweat glands. Each millimetre of a ridge contains 9–18 pores. These pores are permanent, and do not change throughout life. This method of examination is useful when only fragments of fingerprints are available.
Technique of Investigating Fingerprints
The hands are first washed, cleaned and dried. The fingerprints are recorded on an unglazed white paper using printer’s ink. There are two types of prints which are taken: (a) plain fingerprint—is taken by applying ink to the tips of the fingers and placing the fingers directly on paper. In this, the whole contour of the pattern does not appear; (b) rolled fingerprint—is taken by rolling the fingers on papers so as to obtain impression of the whole tip.
Fingerprints on paper, wood and fabric can be developed by treating them with sulphur nitrate solution, and then fixing them with sodium thiosulphate. Fingerprints can also be developed exposing it to the vapours of iodine.
20 Concise Textbook of Forensic Medicine and Toxicology Criminals sometimes attempt to mutilate the patterns of fingerprints by inflicting wounds or burns, application of corrosives but they are not obliterated unless true skin is completely destroyed. Certain diseases like leprosy may modify the finger- prints. Electrical injury and radiation may also cause impairment. In criminal cases, impression of all the 10 fingers are taken, but for civil purposes the left thumb impression is taken in case of males and right thumb impression in case of females.
Footprints: The skin pattern of toes and heels are as distinct and permanent as those of fingers. In case of maternity hospitals, footprints of new- born infants are taken to prevent exchange. Some individuals have also advocated the use of palate- prints and lip-prints in the identification of individuals.
Deformities
They may be congenital or acquired, and are quite useful in the identification of individuals. Deformities like cleft palate, hare-lip, supernumerary fingers of toes, supplementary mammae, web fingers or toes and muscles are congenital. Clear or acquired deformities, such as ununited or malunited fractures are quite useful in the identification of the individual.
Scars
A scar is a fibrous tissue covered by epithelium formed as a result of the healing process of a wound or injury in which there has been a breach of continuity. It does not contain hair follicles, pigment or sweat glands. Generally, a scar assumes the shape of the wound causing it. A scar resulting from an incised wound is usually straight. Broad and irregular scars are caused by lacerated wound. A scar appears in 4 or 5 days after healing under a scab. It is difficult to tell the exact age of a scar. When first formed, a scar is light, tender and covered by a scab. Subsequently, it turns brown and finally white. These changes are generally seen
in 3–4 months. Some scars located in the chest and limbs grow in size with the natural development of the individual, if the injury has been inflicted in childhood.