Micro-Storyteller

Have you ever thought about how random lines on your finger play such a key role in solving murder cases?

These random lines on your fingers are called “fingerprints”. In general terms, fingerprints are the contact impression of the raised portion of the friction ridge skin. The pattern of friction ridge skin on the palms of the hands and soles of the feet is unique to each individual. The event of this friction ridge skin occurs within the womb between the 9th and 24th week of embryo development1.  As each embryo experiences differential growth and pressure within the womb, the last word pattern of the friction ridge skin is different for everyone, whether or not twins, the prints on both children won’t be identical1. These patterns of friction ridges contain many sweat pore rows. The sweat pores allow sweat and oil to urge out from the gland. There are three kinds of natural secretion glands in the body. Each gland produces vastly different amounts of a special sort of sweat, namely, eccrine, sebaceous, and apocrine in everyone. Eccrine sweat glands are found everywhere around the body but are in higher density on palmar and plantar surfaces. Eccrine sweat consists of 98%–99% water, various inorganic salts (such as chloride, bromide, iodide, fluoride, and phosphate), and organic materials (such as amino acids, fatty acids, and urea). Sebaceous glands are found everywhere on the body, except on the friction ridge surface of the hands and thus the feet. Sebaceous glands excrete sebum, which consists of saturated fats, waxes, and squalene. Apocrine glands are found primarily in axillae and anogenital areas of humans, and these glands excrete a viscous milky fluid2. Briefly, the fingerprints were formed if the sweat touched with other substances on the smooth surface.

Fingerprint Types and Patterns

Fingerprints will always be identical throughout our lives until we died. Consistent with growing up, the dimensions of our fingers will be larger but the print on the finger will never change3.  During a family, fingerprints’ general patterns might be the same in level one. But they’re different in levels two and three because they are not inherited. As soon because the formation processing finished the fingerprints, they grow the ridges uniformly altogether directions during their growth process. This is often the reason that the pattern had never been changed. They never change whether or not the skin tissue is torn, it grows back because of the same print before. Commonly, fingerprint patterns are often found in three categories: arches, loops, and whorls1,3,4.

Figure: Three main fingerprint types (a) arch, (b) loop, and (c) whorl

Arches patterns are often found in 5% of all encountered fingerprint patterns. As its shape is the same as the name, the pattern is curved just like the arch. In arches, the ridges move from one part to the other of the print pattern and there are not any reversed turning ridges. Naturally, in an arch pattern, there’ll be no delta. But in some cases, if the delta is made, there’ll be no re-curving ridge between the core and the delta points. Loop patterns are often found in 60% – 70% of all encountered fingerprint patterns. Within the loop pattern, a minimum of one ridge goes inside of the imprint, re-curves or intersects the road joining from the delta to the core and ends the direction at the side where the ridges started. It’s at least one core, one delta and a ridge count for each loop pattern. Whorls are often found in about 25%-35% of all encountered fingerprint patterns. Some ridges turn through a minimum of one circuit. Every pattern of fingerprint containing a minimum of two deltas can be the whorl pattern1,5.

Fingerprint in Criminal Investigation

Roughly, fingerprints are often categorized into three prints: patent (visible) prints, plastic prints and latent(invisible) prints for the investigation of crimes. Patent prints are formed if the fingers touched a surface and therefore the finger ridges are left and merge with a coloured material such as blood, grease, or ink, dirt, lubricant, or some quiet oil and can easily be visible without using any extra microscope. Plastic prints are often observed when the finger rides are left on very sloppy things which can be used for the impression such as putty, paint, wax, and soap, or it’s going to be dust. Sometimes, it’s also called impressed prints. It can also create a three-dimensional impressed print. Due to this impression, it is often seen easily and can take the photograph for print without doing any other development. It also can be used for the detection of the spoof fingerprint. Latent fingerprints can’t be seen easily with the eye and can be made detectable with dusting, fuming or another chemical reagent. It is often created latent fingerprint by the sweat obtained from sebaceous glands of our bodies or water, salt, and amino acids. Latent fingerprints are often collected from many different diversities of surfaces1,3,6. also, invisible fingerprints are often processed to produce visible prints for identification. These invisible prints are usually created from skin oils. The prints can help the detectives to form a case against a suspect even if the prints are partial, smudged, or imperfect. When the crime scene examiner discovered the print from the crime scene, they collected the print.

After they collected the prints from the crime scene, the analysis process started. In other words, it is often seen as comparing unknown print which is collected from the crime scenes with the known print that is stored in the database. During this fingerprint analysis process, if the collected fingerprint isn’t clear, accurate and complete, it can create issues in the fingerprint recognition process. Due to this reason, fingerprint examiners decide whether there’s enough information in the print to be used for recognition or not. The analysis includes determining class characteristics and individual characteristics by comparing one point by one point until they need to find the possibility of a match for the collected unknown print6.

Conclusion

Fingerprints have been used in forensic investigations for the examinations of individuals since the late 19th century. However, it is now clear that fingerprints can provide significantly further information about an individual. Fingerprint plays a key role in community security and criminal investigation, such as forensic investigation, law enforcement, customs access, and public security organs. This can as well help to provide a more enjoyable and secure life to people. Molecules that make up the fingerprint are storytellers, so information on your health, your actions, your lifestyle, and your routines, accessible in a fingerprint. And the molecules are the storytellers of our secrets in just a touch.

References:

  1. Win, K. N., Li, K., Chen, J., Viger, P. F. & Li, K. Fingerprint classification and identification algorithms for criminal investigation: A survey. Future Generation Computer Systems 110, 758–771 (2020).
  2. Hazarika, P. & Russell, D. A. Advances in fingerprint analysis. Angewandte Chemie – International Edition vol. 51 Preprint at https://doi.org/10.1002/anie.201104313 (2012).
  3. Alqadi, Z., Abuzalata, M., Eltous, Y. & Qaryouti, G. M. Analysis of fingerprint minutiae to form fingerprint identifier. International Journal on Informatics Visualization 4, (2020).
  4. Patil, V. & Ingle, D. R. An association between fingerprint patterns with blood group and lifestyle based diseases: a review. Artif Intell Rev 54, (2021).
  5. Militello, C., Rundo, L., Vitabile, S. & Conti, V. Fingerprint classification based on deep learning approaches: Experimental findings and comparisons. Symmetry (Basel) 13, (2021).
  6. Nguyen, H. T. & Nguyen, L. T. Fingerprints classification through image analysis and machine learning method. Algorithms 12, (2019).

Figure Reference: Dermatoglyphics and abnormal palmar flexion creases as markers of early prenatal stress in children with idiopathic intellectual disability – Scientific Figure on ResearchGate. https://www.researchgate.net/figure/Basic-fingerprint-patterns-a-the-arch-is-the-simplest-of-all-the-configurations-b_fig1_11673949

Inspector: Süleyman ŞAHİN

Yorum bırakın

E-posta adresiniz yayınlanmayacak. Gerekli alanlar * ile işaretlenmişlerdir