PHYSICS IN FORENSIC INVESTIGATIONS By N.M. Fatangare

1. PHYSICS IN FORENSIC INVESTIGATIONS By N.M. Fatangare Associate Professor, Head- Forensic Physics Division and Coordinator, Govt. Institute of Forensic Science, A’ Bad. www.gifsa.in Mail ID- nmfatangare@yahoo.com

2. What is Forensic Investigation? • Systematic and Scientific analysis which will lead to root cause of a crime and help in criminal justice delivery system.

3. Crime- • A violation of law in which there is injury to the public or a member of the public and a term in jail or prison, and /or a fine as possible penalties.

4. The crime scenario in the last phase of 20th century has become very complex. • It is further expected to be more complex in the 21st century. • The modus operandis of crime has become scientific due to use of scientific methods in the commission of crime. • It is essential to use science and technology in apprehending the criminals with the tools of science. • The burning problems : white—collar crime including bank scams and scandals, forgeries and frauds in financial institutions, terrorism and explosives, drug menace, computer crime, juvenile crime pertaining to persons and identification of person, firearms and materials.

5. With the origin of man on the earth crime came into being . • Methods of prevention and control of crime persisted in the society in one form or the other. • Social order was maintained in the primitive societies by way of social sanctions, or do’s and don’ts as framed by man in the society . • Increasing physical necessities & meeting their demands – cause of crime.

6. Forensic science- • Latin word forēnsis, - "of or before the forum.” • Is the use of science in a legal setting • Is the use of scientific principles in issues of law • Science of comparison. Suspect / Exhibit <=> Control / Reference

7. Crime Scene-Any physical location in which a crime has occurred or is suspected of having occurred ORA location that may contain evidence of a crime.

8. A - PRIMARY  CRIME SCENE: The original location of a crime or accident.  B - SECONDARY  CRIME SCENE: An alternate location where additional evidence may be found.

9. Crime  Scene Vocabulary • Testimonial evidence: Includes oral or written statements given to police as well as court testimony by people who witnessed an event. • Physical evidence : Any material items that would be present at the crimescene, on the victims, or found in a suspect’s possession.   • Trace  evidence:Physical evidence that is found in small but measurable amounts.

11. Physical Evidence • Automobiles run on fuel -- Crime laboratories on physical / trace evidence. • Encompasses any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its executor. • If it is to be used effectively, its presence first must be recognized at the crime scene.

12. Trace Evidence • Hair • Fiber • Glass • Paint • Dust • Dirt • Chemicals • Firearms • Fluids • Blood • Bite Marks • Shoe Prints • Tool Marks • Wounds • Documents • Fingerprints

13. 1. Cell Phone Forensics:- Crimes involving mobile phones. 2. Computational Forensics:- Development of algorithms and software to assist forensic examination. 3. Explosive:- Study of physical/chemical/ atomic properties of explosive materials 4. Hydrocarbon Forensic:- Study of petroleum product. 5. Criminalistics:- Application of various sciences to answer questions relating to examination and comparison of biological evidence, trace evidence, impression evidence (fingerprints, footwear impressions, tire tracks etc.), controlled substances, ballistics, firearm and tool mark examination, and other evidence in criminal investigations. 6. Digital Forensics:- Scientific methods and techniques in order to recover data from electronic / digital media. 7. Narcotics:- Study of illegal cultivation / manufacturing of narcotic substance.

14. 8. Forensic Accounting:- Study and interpretation of accounting evidence • Forensic Aerial Photography:- Study and interpretation of aerial photographic evidence. • Forensic Anthropology :- For the recovery and identification of skeletonised human remains. • Forensic Archaeology:- Archaeological techniques in forensic investigations. 12. Forensic Artists & sculptors:- Drawing sketches a suspect on eyewitness information. Forensic sculptors reconstruct faces, usually in modelling clay or on a computer from skulls or other fragments.

15. 13. Forensic Astronomy:- Uses methods from astronomy to determine past celestial constellations for forensic purposes. 14. ForensicBallistics:-Study of the flight paths of projectiles / bullets. 15. Forensic Behavioral Science: Family law cases---such as those involving domestic violence, the custody of children and juvenile delinquency. 16. Forensic Bioinformatics:- Study of biological data for criminal investigation 17. Forensic Botany :- Study of plant life in order to gain information regarding possible crimes. 18. Forensic Chemistry:- Study of detection and identification of illicit drugs, accelerants used in arson cases, explosive and gunshot residue etc. 19.Forensic Cheiloscopy: - Study of Lip prints.

16. 20. Forensic Dactyloscopy:- Study of fingerprints. 21 . Forensic document examination :- Study about a disputed documents using a variety of scientific processes and methods. The most common type of examination involves handwriting, trash marks, VSC etc. • Forensic DNA analysis:- Takes advantage of the uniqueness of an individual's DNA to answer forensic questions such as paternity/maternity testing and placing a suspect at a crime scene, e.g. in a rape investigation. 23. Forensic Engineering:- is the scientific examination and analysis of structures and products relating to their failure or cause of damage. 24. Forensic Entomology:- Deals with the examination of insects in, on and around human remains to assist in determination of time or location of death. It is also possible to determine if the body was moved after death.

17. 25. Forensic Geology or Geo-Forensic :- Deals with trace evidence in the form of soils, minerals, petroleum and Burials 26. Forensic Geophysics:- Application of geophysical techniques such as radar for detecting objects hidden underground or underwater. 27. Forensic intelligence:- process starts with the collection of data and ends with the integration of results within into the analysis of crimes under investigation 28. Forensic Interviews:- are conducted using the science of professionally using expertise to conduct a variety of investigative interviews with victims, witnesses, suspects or other sources to determine the facts regarding suspicions, allegations or specific incidents in either public or private sector settings.

18. 29. Forensic Instrumentation:- It is emerging branch of forensic sciences under which duplicacy of different equipments which may be mechanical, electrical, electronic are examined and identified. 30. Forensic Litigation Science:- describes analysis or data developed or produced expressly for use in a trial versus those produced in the course of independent research. 31. Forensic Limnology:- is the analysis of evidence collected from crime scenes in or around fresh-water sources. Examination of biological organisms, in particular diatoms, can be useful in connecting suspects with victims. 32. Forensic Linguistics:- deals with issues in the legal system that requires linguistic expertise. Analyse the content of written or oral communication to identify the culprit and they can determine whether two communications are from the same person. This is found useful in various cases involving matching notes and handwritten contents.

19. 33. Forensic Mathematics and Statistics:- For understanding of the calculations associated with the analysis of experimental work, including an emphasis on the use of graphs and the evaluation of uncertainties and probabilities. 34. Forensic Meteorology:- is a site-specific analysis of past weather conditions for a point of loss. 35. Forensic Microbiology:- study of microorganism in crime analysis. 36. Forensic Odontology:- is the study of the uniqueness of dentition, better known as the study of teeth. 37. Forensic Optometry:- is the study of glasses and other eye wear relating to crime scenes and criminal investigations 38. Forensic Pathology:- is a field in which the principles of medicine and pathology are applied to determine a cause of death or injury in the context of a legal inquiry. 39. Forensic Physics:- It identifies metal, precious metals from their physical properties and also examines building materials, tool marks, glass and paints, electronic /electrical devices / circuits etc. for quality in different crime cases and for identification of the source.

20. 40. Forensic Podiatry:- is an application of the study of footprint / footwear and their traces to analyse scene of crime and to establish personal identity in forensic examinations. 41. Forensic Psychiatry:- is a specialised branch of psychiatry as applied to and based on scientific criminology. 42. Forensic Psychology:- is the study of the mind of an individual, using forensic methods. Usually it determines the circumstances behind a criminal's behaviour. 43. Forensic Seismology:- is the study of techniques to distinguish the seismic signals generated by underground nuclear explosions from those generated by earthquakes. 44. . Forensic Serology:- is the study of the body fluids. 45. Forensic Thanthology:- Study of death

21. 46 .Forensic toxicology:- is the study of the effect of drugs and poisons on/in the human body. 47.Forensic video analysis:- is the scientific examination, comparison and evaluation of video in legal matters. 48. Forensic Voice / Speaker Identification:- Voice / speech analysis. 49.Mobile device forensics:- is the scientific examination and evaluation of evidence found in mobile phones, e.g. Call History and Deleted SMS, and includes SIM Card Forensics 50.Trace evidence analysis:- is the analysis and comparison of trace evidence including glass, paint, fibres and hair. 51.Wildlife Forensic Science:- applies a range of scientific disciplines to legal cases involving non-human biological evidence, to solve crimes such as poaching, animal abuse, and trade in endangered species. 52. Nuclear Forensic:- Deals with Physical, Isotopic and Chemical analysis of radioactive materials. 53. Environmental Forensic:- Scientific investigations that address contamination within the environmental media of air, water, soil and biota, and is subject to law court, arbitration, public debate, or formal argumentation. 54. Paleontology – Study of natural fossils

22. Ballistics • The study of the functioning of firearms. • The study of the firing, flight, and effects of ammunition. • The study of the dynamics of projectiles. • The study of the flight characteristics of projectiles. • Impact on target

23. Ballistics - Types Internal External Terminal

31. Internal Ballistics • Deals with the motion of a bullet in the bore of the weapon. • Ignition- Striking of firing pin on percussion cap • Burning of propellant (Gun Powder- KMNO4 + S + Charcoal )– Chemical reaction resulting in production and expansion of gasses. • Pressure – High pressure is generated. PV= nRT ; T=2000 C

32. FEDERAL CARTRIDGE CASE PRIMER CUP F C ANVIL FLASH HOLE CONTACT EXPLOSIVES Louise Walzer, JPSO Crime Lab

33. Firing Pin Striking Primer Louise Walzer, JPSO Crime Lab

34. - The firing pin is recessed The firing pin strikes the primer, sending the bullet down the barrel. The back of the primer is slammed back onto the breech. Louise Walzer, JPSO Crime Lab

37. 4. Muzzle velocity (V) - Pressure exerted on the back surface of the bullet gives muzzle velocity. V= K[ L(1 – r -1/4) + ( G+ L/3)]1/2 Where –K - Constant of system r - Expansion ratio L & G - charge and bullet weight in grains. 5. Density of loading- w.r.t. water Less- miss firing High – Bursting of firearm

38. 6. Bullet Fit-

39. 7. Twist of rifling – Spinning motion of bullet due to land on bullet and grooves in barrel. Eb = Ef + Es Eb- Total energy Ef – Energy due to forward motion Es – Energy due to spin motion

40. 8. Strength– Erosion - Corrosion of Barrel

41. 9. Jump , Vibration , Burst 10. Recoil – Conservation of momentum MwVw = MpVp +McVc Where, Mw- mas of weapon Vw- recoil velocity of weapon Mp- mass of projectile Vp- velocity of projectile Mc –mass of gun powder Vc- velocity of gun powder charge

42. Exterior Ballistics • Motion from muzzle end to target / falls on ground due to gravity. • Flight of all projectiles through the air is governed by N’s laws of motion. • Trajectory – Parabolic

43. Trajectory Y To ∞ …. ? D D’ C C’ B B’ Bullet Drop A A’ α H R/2 R/2 X R

44. Factors governing the flight of bullet- • Gravity and Air resistance – Parabolic Trajectory. • Horizontal Range (R) = V2 Sin 2α / g Where, V- Muzzle velocity α – Projection angle g – Acceleration due to gravity • Vertical Range – H= V2 Sin2α / 2g • Time taken by the bullet to hit the ground- H= ut + ½ gt2 = ½ gt2 t = ( 2H/g)1/2

45. Maximum Horizontal range ( R max)- When α = 450i.e 2 α= 900 i.e Sin 2 α= 1 R max = V2 / g • Practically - α = 290to 300 • Horizontal Range at projection angle ( 45+ θ ) = ( 45- θ ) V2 Sin 2( 45+ θ ) / g = V2 Sin 2( 45- θ ) / g V2 Sin (90+2 θ ) / g = V2 Sin (90-2 θ ) / g V2 Cos( 2θ ) / g = V2 Cos( 2θ ) / g

47. b. Wind deflection:Deflection of the shot is D= W(T- R/V) W- Cross component of the wind, T- Time of flight, R- Range, V- Muzzle velocity

48. c. Canting • Twisting the weapon to the right or to left, which is likely to fire the bullet to the right or to the left • Effect of cant = Drop X Sin α

49. d. Gyroscopic Drift – Gradual deviation of a bullet from its intended path due to its spinning motion imparted by rifling of the barrel.

50. e. Velocity of a bullet-Vertical component – V Sin α - g t Horizontal component - V Cos α Resultant Velocity – ( V2-2V g t Sin α + g2t2) 1/2