Forensic Field

Short Notes: ● The raw material for the production of heroin is opium, a naturally occurring product of the plant Papaver somniferum L. (opium poppy). The green seed heads are cut to release a milky latex which contains morphine. ● MDMA is the most common drug encountered in ‘ecstasy’ tablets. MDMA causes euphoria, a feeling of empathy, increased energy and tactile sensation. ●Benzodiazepines express their pharmacological activity by binding to the so-called GABAA receptor which mediates the effect of gammaaminobutyric acid (GABA), the inhibitory neurotransmitter in the brain. ●The main psychoactive compound in cannabis and cannabis resin is D9-tetrahydrocannabinol (D9-THC) ●The base form of cocaine – ‘crack cocaine’ is readily prepared from cocaine hydrochloride using baking soda and water.

NTA announces the opening of the online portal for the submission of the Online Application Form for UGC - NET June 2024. UGC-NET is a prestigious test conducted by the National Testing Agency (NTA) on behalf of the University Grants Commission (UGC). This test determines the eligibility of Indian nationals for the award of a Junior Research Fellowship, appointment as Assistant Professor, and admission to Ph.D. programs in Indian universities and colleges. The application process will be open from 20th April 2024 to 10th May 2024. Candidates are advised to carefully follow the instructions provided in the Information Bulletin and on the NTA website. The examination is scheduled for 16th June 2024. For more details and updates, please visit our official website.

Fibers Fibers fall into two categories: 1. Natural and, 2. Synthetic. Both types are used in the manufacture of commercial products of a wide variety, ranging from all types of apparel, automobile seat covers, and home, office, toys, and automobile coverings. All commercial offerings typically provide an immense variety of styles and colors to choose from. To a significant degree, all such fiber and the commercial processes used to produce the fiber itself and its applications are patented and collected in massive proprietary databases maintained by manufacturers. Although not generally available to police authorities or the public at large, these database collections are typically available to forensic experts on a cooperative, case-by-case basis by the international fiber industry. Fibers come in three basic categories: 1. Animal, 2. Vegetable, and, 3. Mineral. Natural fibers thus include animal fibers such as wool, silk, and furs Vegetable fibers include cotton, linen, jute, hemp, and sisal. Mineral fibers include asbestos, glass, wool, and fiberglass. The number of synthetic fibers is legion, including acetates, acrylics, nylons, polyester, spandex, and a host of others. These are the types of fibers that can be located at a crime scene and subsequently identified as to type and commercial application, if need be.

MCQs on Microscope 1. Which part of the compound microscope helps in gathering and focusing light rays on the specimen to be viewed? a) Eyepiece lens b) Objective lens c) Condenser lens d) Magnifying lens 2. What is the minimum distance for the eye to focus any object? a) 11 cm b) 25 cm c) 32 cm d) 42 cm 3. Resolving power of a microscope is a function of ____ a) Wavelength of light used b) Numerical aperture of lens system c) Refractive index d) Wavelength of light used and numerical aperture of lens system 4. The greatest resolution in light microscopy can be obtained with ___ a) Longest wavelength of visible light used b) An objective with minimum numerical aperture c) Shortest wavelength of visible light used d) Shortest wavelength of visible light used and an objective with the maximum numerical aperture 5. Oil immersion objective lens has an NA value of____ a) 0.65 b) 0.85 c) 1.33 d) 1.00 6. In fluorescence microscopy, which of the following performs the function of removing all light except the blue light? a) Exciter filter b) Barrier filter c) Dichroic mirror d) Mercury arc lamp 7. Total Magnification is obtained by __ a) Magnifying power of the objective lens b) Magnifying power of eyepiece c) Magnifying power of condenser lens d) Magnifying power of both the objective lens and eyepiece 8. In light microscopy, which of the following is used as fixatives prior to staining technique? a) Osmic acid b) Glutaraldehyde c) Heat d) Osmic acid, glutaraldehyde, heat 9. In Phase contrast microscopy, the rate at which light enters through objects is __ a) Constant b) Inversely proportional to their refractive indices c) Directly proportional to their refractive indices d) Exponentially related to their refractive indices 10. Which part of the light microscope controls the intensity of light entering the viewing area? a) Coarse adjustment screw b) Fine adjustment screw c) Diaphragm d) Condenser lens

Types of Microscopes 1. Simple Microscope 2. Compound Microscope 3. Phase Contrast Microscope 4. Fluorescence Microscope 5. Electron Microscope 6. Scanning Electron Microscope (SEM) 7. Transmission Electron Microscope (TEM) 8. Dark Field Microscope 9. Dissecting Microscope (Stereo Microscope) 10. Digital Microscope 11. Scanning Probe Microscope (SPM) 12. Atomic Force Microscope (ATM) 13. Inverted Microscope 14. Acoustic Microscope 15. X-Ray Microscope 16. Polarizing Microscope 17. Metallurgical Microscope 18. Pocket Microscope 19. USB Microscope 20. Confocal Microscope 21. Laser Scanning Microscope 22. Differential Interference Contrast Microscope (DIC) 23. Near-field Scanning Optical Microscope (NSOM) 24. Raman Microscope 25. Super-resolution Microscope 26. Cryo-electron Microscope 27. Time-lapse Microscope There is a wide range of microscopy techniques and instruments used in various fields of science and research.

1. Who did give principle of exchange and write about it? Ans- Edmond Locard gave principle of exchange. He told, “every contact leaves trace” Or in simple words he said “when two objects come into contact with each other a cross-transfer of material occur.” 2. What is the principle of uniqueness? Ans- Principle of uniqueness told that everything in this world is unique even nature does not duplicate the live things. All human beings are different even monozygotic twins they look exactly alike but somewhere they are different from each other. Leaves of same branch at plant also are having different. So, this is the individuality of the nature. 3. Give definition of Forensic Science? Ans- Forensic Science is an applied science. In this science all the principles of basic science (Physics, Chemistry, Biology, mathematics etc) are utilized for the purpose of law and administration. 4. What is the principle of Analysis? Ans- This principle emphasizes the necessity of correct sampling and packing of the physical evidences. This principle states, “The analysis can be no better than the sample analyzed”. On the basis of this principle different physical evidences are analyzed in the Forensic Science Laboratory. 5. What is the law of comparison? Ans- Likes can be compared with likes. According to this principle “only the same exhibits must be compared with the same.” Things which are different from each other in every point such as appearance, morphology, texture, shape, size, color, chemical components and biological characters, but if they are having some similarities they can be compared. So, this is the principle of comparison that emphasizes the necessity of providing like exhibits for comparison with the suspected one. 6. What is law of probability? Ans- This law determines the chances of occurrence of a particular event in a particular way out of a number of ways in which the event can take place or fail to take place with the equal facility. Forensic scientist always apply the law of probability with the physical evidence like if forensic scientist receives the blood and other biological fluid as physical evidence then what will be the probability of the blood that is belong to so and so person. 7. What is law of progressive change? Ans- This law states, “Everything changes with passage of time”. Or in other word we can say that nothing is permanent, until or unless one day it will change from one form to another. 8. Explain principle of linkage. Ans- According to this principle if investigating officer gets the physical evidence at the crime scene, one can easily link a suspect to a victim. On the basis of physical evidence, there can be two type of linkage- direct linkage or indirect linkage. Apart from suspect or victim linking it also link suspect to the crime scene, suspect with physical evidence.

General Forensic Science Quiz 1. Principle of exchange is given by a) Edmond Locard b) Sharma B R c) Sharma J D d) None Ans- a 2. Which system is used for the examination of fingerprints? a) Vahan samanvay b) AFIS c) SPM d) None Ans- b 3. For the comparison of tool marks which instrument is useful? a) Compound Microscope b) HPLC c) GC d) Comparison Microscope Ans- d 4. In paternity disputes which principle/s of Forensic Science are useful a) Law of Probability b) Law of comparison c) Both a and b d) None Ans- c 5. Physical evidences are preserved because; a) Everything changes with passage of time b) Everything is unique c) Everything in this world can be compared d) None of above Ans- a

CRIME SCENE PROCESSING: A crime scene consists of the location of occurrence, any means of transport of a victim, any secondary locations (graves, dump sites, etc.) and the victim (him or herself). The purpose of examining a crime scene is fourfold: 1. To prove or disprove that a crime occurred. 2. To collect physical evidence linking a suspect(s) to the victim or crime scene or to link the victim and/or suspect to a primary or secondary crime scene. 3. To collect physical evidence which will help reconstruct the circumstances involved in the incident. 4. To provide investigative leads which can result in information on the victim and suspect(s). The various techniques for crime scene processing are determined by the nature of the crime and the location of the crime scene. These techniques are covered in various texts and in in-service and on-the-job training. The investigating officer should consider a number of criteria relating to physical evidence while examining a crime scene. 1. Anything that is present in a crime scene can be physical evidence. Not all physical evidence is readily visible (latent fingerprints, shoe prints, trace evidence, etc.). 2. Minimum disturbance to the scene by non essential personnel is critical. They can remove, alter, destroy or add physical evidence to the scene. 3. The best means by which to secure a crime scene or item of evidence is to restrict access and avoid disturbance of the area. Limited entry into a scene is essential as well as minimum manipulation of items. 4. Recognition of something as physical evidence is a major factor in crime scene processing. Experience and training is important. 5. Documentation by measurements, notes and photography is necessary. 6. No item of evidence should be handled until its position in the scene, positions of any mechanical devices (on-off switches, safeties, hammers, etc.) and possible trace evidence has been evaluated and documented. 7. Collect all items of evidence. When in doubt, collect. These items can be sorted out later. The investigator normally has one chance to process the crime scene. 8. All items of physical evidence must be collected and preserved in such a manner as to: A. Avoid alteration, damage or loss of information B. Prevent contamination (trace evidence) C. Prevent spoilage/decomposition (biological samples) 9. Non removable physical evidence must be collected/documented in some other fashion: A. Photography (close-up, specialized lighting, etc.) B. Casts (toolmarks) C. Lifts (latent fingerprints, shoe prints) 10. The relationship of the physical evidence to the crime scene and circumstances of the crime must be explainable. Non explainable or overlooked physical evidence can result in a different interpretation of the crime scene.

Computer Based Crimes This is criminal activity that is conducted purely on computers, for example cyber-bullying or spam. Computer Facilitated Crime Crime conducted in the "real world" but facilitated by the use of computers.