1. Analyzing the Crime Scene Chapter 2 Forensic Science bsapp.com

2. Approaching a Crime Scene bsapp.com

3. Vocabulary to Know First responder First responder Individual evidence Individual evidence Paper bindle Paper bindle Primary crime scene Primary crime scene Secondary crime scene Secondary crime scene Trace evidence Trace evidence Direct evidence Direct evidence Inductive reasoning Inductive reasoning Deductive reasoning Deductive reasoning Chain of Custody Circumstantial evidence Class evidence Crime scene investigation Crime scene reconstruction modus operandi

4. Locard’s Exchange Principle Established by Dr. Edmond Locard Director of 1 st forensic lab in Lyon, France. States: when a person comes in contact with an object or another person, a cross-transfer of physical evidence occurs. The evidence is known as trace evidence. "It is impossible for a criminal to act, especially considering the intensity of a crime, without leaving traces of this presence."

5. Types of Trace Evidence Hair Fibers Skin cells Pollen Glass fragments Paint chips Makeup, etc.

6. Classifying Evidence Direct Evidence: Direct Evidence: 1 st hand observations; eyewitness video. 1 st hand observations; eyewitness video. Circumstancial evidence: Circumstancial evidence: Indirect evidence implies fact but doesn’t prove. Indirect evidence implies fact but doesn’t prove. 2 types – physical and biological 2 types – physical and biological

7. Classifying Evidence - Circumstancial Biological (more pursuasive) Biological (more pursuasive) Body fluids Body fluids Hair Hair Plant parts Plant parts Natural fibers Natural fibers Blood Blood Physical Impressions Fingerpints, shoeprints, tire prints,tool marks. Synthetic fibers Shell casings Bullets Weopons Also called Indirect Evidence

8. Classifying Evidence Class Evidence Place evidence into groups. Make or model or objects Individual Evidence Place evidence to an individual person or thing.

9. Approaching a Crime Scene Personal Safety and the well being of victims is paramount. Personal Safety and the well being of victims is paramount. Secure / Preserve and Isolate the crime scene. Video Secure / Preserve and Isolate the crime scene. VideoVideo Record the crime scene in photos, sketches and notes. Record the crime scene in photos, sketches and notes. bsapp.com

10. CSI Team Police officers Police officers CSI CSI Recorders, sketch artists, photographers, evidence collectors. Recorders, sketch artists, photographers, evidence collectors. ME (medical examiner) ME (medical examiner) Detectives Detectives Specialists Specialists Entomologist, psychologists, anthropologists Entomologist, psychologists, anthropologists

11. 7 S’s of CSI Secure crime scene Secure crime scene Separate witnesses Separate witnesses Scan scene Scan scene Seeing the scene Seeing the scene Sketch the scene Sketch the scene Searching for evidence Searching for evidence Securing and collecting evidence Securing and collecting evidence

12. 7 S’s: Secure the Crime Scene Done by 1 st responder Restrict all unauthorized persons from entering cs. Keep security log of all who visit cs. Keep evidence from getting contaminated.

13. 7 S’s: Separating Witnesses Keep witnesses from comparing or creating a story (collusion). Keep witnesses from comparing or creating a story (collusion). Ask each witness the following ?’s. 1. when did the crime occur? 2. Who called in the crime? 3. Who is the victim? 4. Can the perp. be identified? 5. What did you see happen? 6. Where were you when you observed the crime?

14. 7 S’s: Scanning the Scene Scan scene to determine where photos need to be taken. Scan scene to determine where photos need to be taken. May occur at both primary & secondary cs. May occur at both primary & secondary cs.

15. 7 S’s: Seeing the Scene CS examiner must see (observe) the scene. Photos must be taken w/ & w/o measuring ruler. Triangulation of stationary obj. should be included as reference pts. View cs from several different angles.

16. Recording the Crime Scene Photographs /videos Photographs /videosvideos Software. Software. Software Sketches Sketches Notes Notes Notes bsapp.com

17. Photography Scene Scene Multiple views Multiple views Entrances Entrances Exits Exits Windows Windows  Evidence  Close ups  Perspectives  Multiple angles bsapp.com Different Wavelengths of photography: IR or UV

18. 7 S’s: Sketching the Scene Rough Sketch Rough Sketch Should include: Should include: a. Position of any evidence or victim. b. All objects measured from two stationary landmarks c. North labled d. Scale of distance provided e. Any objects in vicinity of cs. (doors, windows, furniture) f. If outdoors, position of trees, vehicles, hedges, and other structures should be included. Final Sketch Very accurate; could be used in court. In addition to RS include: a. Case # b. Date c. Location d. Name

19. Rough Sketch of the Crime Scene The initial documentation of the crime scene. The initial documentation of the crime scene. Often a hand drawn representation of the scene by investigators. Often a hand drawn representation of the scene by investigators.

20. Rough Sketch to Final bsapp.com A computer drawn CAD version of the combination of the rough sketch and notes from the investigators.

21. Sketch Examples

22. 7 S’s: Searching for Evidence Search patterns: Search patterns: a. Grid b. Linear c. Quadrant or Zone d. Spiral Single investigater may use grid, linear or spiral. Single investigater may use grid, linear or spiral. Group – linear, zone or quadrant. Group – linear, zone or quadrant. Flashlight & forceps are equipment of choice. Keeps from picking up extraneous materials. Flashlight & forceps are equipment of choice. Keeps from picking up extraneous materials.

23. Notes Match to sketch Match to sketch Use a numbered key Use a numbered key Quick, short, bulleted Quick, short, bulleted What can you not see from the photo? What can you not see from the photo? Critical Observations of the scene. Use all senses. Critical Observations of the scene. Use all senses. bsapp.com

24. Types of Search Patterns

25. 7 S’s: Securing & Collecting Must be properly packaged, sealed & labeled Must be properly packaged, sealed & labeled 1. Packaging Examples: Liquids & arson: stored in airtight, unbreakable containers Liquids & arson: stored in airtight, unbreakable containers Most biologicals: breathable containers so evidence can dry out – reduces chance of mold contamination. Package in paper bindles. Most biologicals: breathable containers so evidence can dry out – reduces chance of mold contamination. Package in paper bindles. Once proper containers are used, place in plastic or paper container. Then: Once proper containers are used, place in plastic or paper container. Then: a. Seal with tape. b. Label across tape by collector c. Evidence log & chain of custody attached to evidence container.

26. 7 S’s: Securing & Collecting 2. Evidence Log includes: a. Case # b. Item inventory # c. Description of evidence d. Name of suspect e. Name of victim f. Date & time of recovery g. Signature person recovering evidence h. Signature of any witness present during collection.

27. Collecting Evidence Victim's clothing Victim's clothing Fingernail scrapings Fingernail scrapings Head and pubic hairs Head and pubic hairs Blood (for typing and DNA purposes) Blood (for typing and DNA purposes) bsapp.com VideoVideo FBI training film

28. Vaginal, anal, and oral swabs Vaginal, anal, and oral swabs Recovered bullets from the body and/or surrounding area Recovered bullets from the body and/or surrounding area Hand swabs or washings from shooting victims Hand swabs or washings from shooting victims bsapp.com

29. Buccal Swab A buccal swab, also known as buccal smear, is a way to collect DNA from the cells on the inside of a person's cheek. Buccal swabs are a relatively non-invasive way to collect DNA samples for testing. Buccal means cheek or mouth.

30. 7 S’s: Securing & Collecting 3. Packaging Evidence A. Choose appropriate size sheet of clean paper for bindle. B. Crease paper in grid pattern C. Place evidence in center grid D. Fold in left then right sides E. Fold over top & bottom F. Insert top flap into bottom flap & tape closed. G. Place bindle inside plastic/paper bag. Fold bag closed. VideoVideo H. Place seal over folded edge of evidence bag. I. Collector writes name over folded edge. Remember: large, wet object should be placed in paper container & sealed to allow for air drying. Control samples must also be taken from victim for the purpose of exclusion.

31. Chain of Custody Chain of custody (CoC), in legal contexts, refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence. Chain of custody (CoC), in legal contexts, refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence. paper trailevidence paper trailevidence Particularly important in criminal cases, the concept is also applied in civil litigation – and sometimes more broadly in drug testing of athletes, traceability of food products and to provide assurances that wood products originate from sustainably managed forests. Particularly important in criminal cases, the concept is also applied in civil litigation – and sometimes more broadly in drug testing of athletes, traceability of food products and to provide assurances that wood products originate from sustainably managed forests.traceabilitysustainably managed foreststraceabilitysustainably managed forests

32. Chain of Custody *Very Important* Individual that finds the evidence marks it for identification & bags evidence in plastic/paper container. Individual that finds the evidence marks it for identification & bags evidence in plastic/paper container. Placed in final container & labeled with pertinent info. Placed in final container & labeled with pertinent info. Container is sealed & collectors signature across sealed edge Container is sealed & collectors signature across sealed edge Pass onto person that will transport to lab who signs it over to technichian. Pass onto person that will transport to lab who signs it over to technichian. Tech opens packaging at some other location except where originally sealed. After examination, evidence is repackaged in original container where it was removed & placed in a new package. Seal new packaging with techs signature on seal. Tech also signs chain of custody log attached to package.

33. Analyzing Evidence processed by tech that specializes in specific areas of forensic science processed by tech that specializes in specific areas of forensic science Evidence results sent to lead detective Evidence results sent to lead detective Crime Scene Reconstruction Crime scene reconstruction completed using evidence (before crime to its completion) Evidence used to co-oberate witness accounts Direct evidence more compelling than circumstancial. Staged Scenes Poses unique problems. Evidence doesn’t match witness testimony. Common staging situations.

34. Inductive and Deductive Reasoning Induction and deduction reasoning methods. Arguments based on experience or observation are best expressed inductively, while arguments based on laws or rules are best expressed deductively. Inductive reasoning moves from specific details and observations to the more general underlying principles of who did it. Induction and deduction reasoning methods. Arguments based on experience or observation are best expressed inductively, while arguments based on laws or rules are best expressed deductively. Inductive reasoning moves from specific details and observations to the more general underlying principles of who did it. deductive reasoning typically moves from general truths to specific conclusions deductive reasoning typically moves from general truths to specific conclusions

35. Inductive vs. Deductive

36. Inductive vs Deductive Reasoning

37. Police Sketches of Criminals Police sketch artists will convert a victim or eyewitness description to a depiction of the suspect. Police sketch artists will convert a victim or eyewitness description to a depiction of the suspect. Video Video Video

38. Draw This Face:

39. Level Types of Evidence: Class or Individual Class level evidence is a characteristic of evidence that points to a group of objects or people. Example: new tennis shoes… that lots of people could have. Class level evidence is a characteristic of evidence that points to a group of objects or people. Example: new tennis shoes… that lots of people could have. Individual level evidence is a characteristic of evidence that pinpoints a singular person or object. Example: DNA Individual level evidence is a characteristic of evidence that pinpoints a singular person or object. Example: DNA Video Video Video

40. Crime Scene Evidence There are many different types of evidence found at a crime scene. Any of these could be a significant piece in solving the crime. The significance of each piece of evidence is often unknown until after the evidence has been bagged, labeled, and sent to the lab. There are many different types of evidence found at a crime scene. Any of these could be a significant piece in solving the crime. The significance of each piece of evidence is often unknown until after the evidence has been bagged, labeled, and sent to the lab. For these reasons, forensic scientists treat each and every piece of evidence as if it is vital. Every object at a crime scene is considered to be significant until toughly examined. For these reasons, forensic scientists treat each and every piece of evidence as if it is vital. Every object at a crime scene is considered to be significant until toughly examined.

41. Types of Analysis Comparison : Most types of evidence require a control with which to be compared (example: fingerprints, hairs) Comparison : Most types of evidence require a control with which to be compared (example: fingerprints, hairs) Visual : vidence that can be utilized or compared through unaided observation, (example: fingerprints, tool marks) Visual : Evidence that can be utilized or compared through unaided observation, (example: fingerprints, tool marks) Microscopic (trace) analysis that evidence that must be observed with the use of some type of microscope (example: hairs, fibers) Microscopic (trace) analysis that evidence that must be observed with the use of some type of microscope (example: hairs, fibers) Chemical If an article of evidence must be subjected to chemical analysis (example: DNA typing, drug screening). Can be Trace Evidence Chemical : If an article of evidence must be subjected to chemical analysis (example: DNA typing, drug screening). Can be Trace Evidence

42. Common Types of Physical Evidence Documents. Documents. Any document, handwritten or printed, will be submitted so that authenticity and source can be determined. These types of analysis are utilized mainly with ransom notes, suicide notes, death threats, and forgeries. Glass. Glass panes, particles, or fragments that are found or transferred to a person or object involved in a crime may be substantial evidence. Such evidence, whether broken by a bullet or fingerprints, may link a suspect or piece of evidence to a crime scene, and be used to deduce cause of breakage or direction of penetration. Glass. Glass panes, particles, or fragments that are found or transferred to a person or object involved in a crime may be substantial evidence. Such evidence, whether broken by a bullet or fingerprints, may link a suspect or piece of evidence to a crime scene, and be used to deduce cause of breakage or direction of penetration. Fingerprints a mainstay in criminal investigating. When a person touches an article with their bare hands that a print is left behind. Such prints are called latent prints. with the utilization of computers and large databases, identifying a suspect’s prints have become routine. Fingerprints a mainstay in criminal investigating. When a person touches an article with their bare hands that a print is left behind. Such prints are called latent prints. with the utilization of computers and large databases, identifying a suspect’s prints have become routine.

43. Common Types of Physical Evidence Hairs are often found at a crime scene and are fairly easy to compare and identify with the use of a microscope. Any animal or human hair present at the scene could link a person or animal with a crime. With a number of samples to compare, hairs from a crime scene may be matched to a suspect with a high degree of certainty. Upon the discovery of a root or follicle tissue, DNA analysis can provide an exact match. Hairs are often found at a crime scene and are fairly easy to compare and identify with the use of a microscope. Any animal or human hair present at the scene could link a person or animal with a crime. With a number of samples to compare, hairs from a crime scene may be matched to a suspect with a high degree of certainty. Upon the discovery of a root or follicle tissue, DNA analysis can provide an exact match. Body or parts are often found in scenes that involve the most serious of crime. DNA, Anthropology, Odontology can reveal the identity. Body or parts are often found in scenes that involve the most serious of crime. DNA, Anthropology, Odontology can reveal the identity.

44. Common Types of Physical Evidence Soils, Minerals, Wood, and Other Vegetative Matter. Any items containing soil, minerals, wood, or other vegetative matter could link a person or object to a particular location (for example, soil imbedded in shoes and vault insulation found on garments). Soils, Minerals, Wood, and Other Vegetative Matter. Any items containing soil, minerals, wood, or other vegetative matter could link a person or object to a particular location (for example, soil imbedded in shoes and vault insulation found on garments). Fibers are any natural or synthetic fiber transferred which may be useful in establishing a relationship between objects and/or persons. They may be able to predict if such a fiber originated from clothes, towels, carpet, or other sources. Fibers are any natural or synthetic fiber transferred which may be useful in establishing a relationship between objects and/or persons. They may be able to predict if such a fiber originated from clothes, towels, carpet, or other sources.

45. Common Types of Physical Evidence Firearms as well as ammunition, are often important evidence in an investigation. In fact, it is often impossible to get a conviction in shooting cases without the discovery of such evidence. Firearms as well as ammunition, are often important evidence in an investigation. In fact, it is often impossible to get a conviction in shooting cases without the discovery of such evidence. Powder Residue. Powder Residue. A person or item may be suspected of containing firearm discharge residue. The presence and disbursement of powder residue is used to discern if, when, and where a firearm may have been fired.

46. Common Types of Physical Evidence Explosives and petroleum products. These products are devices containing an explosive charge, as well as all objects removed from the scene of an explosion or fire that are suspected to contain the residues of an explosive material. The placement and appearance of these items is significant in determining where a fire or explosion originated and advanced. After collection and analysis, the chemical composition of such may be helpful identifying the origin and users of the substances. Explosives and petroleum products. These products are devices containing an explosive charge, as well as all objects removed from the scene of an explosion or fire that are suspected to contain the residues of an explosive material. The placement and appearance of these items is significant in determining where a fire or explosion originated and advanced. After collection and analysis, the chemical composition of such may be helpful identifying the origin and users of the substances. Video

47. Common Types of Physical Evidence Impressions and Tool Marks. Impressions include tire markings, shoe prints, depressions in soft soils, and all other forms of tracks, glove and fabric impressions, and bite marks in skin or foodstuffs. Impressions and Tool Marks. Impressions include tire markings, shoe prints, depressions in soft soils, and all other forms of tracks, glove and fabric impressions, and bite marks in skin or foodstuffs. Drugs. Any substance in violation of laws regulating the sale, manufacture, distribution, and use of drugs or chemicals will be seized. Drugs. Any substance in violation of laws regulating the sale, manufacture, distribution, and use of drugs or chemicals will be seized. In addition to the large number of illegal drugs which are manufactured, sold, and used, a large number of perpetrators committing other crimes In addition to the large number of illegal drugs which are manufactured, sold, and used, a large number of perpetrators committing other crimes

48. Common Types of Physical Evidence Paint. Any paint, wet or dry, may be transferred from the surface of one object to another during the perpetration of a crime. Most paint evidence originates from crimes involving hit-and-runs. With a control sample to compare a suspected sample, paint can be matched to a vehicle with near 100% certainty. Paint. Any paint, wet or dry, may be transferred from the surface of one object to another during the perpetration of a crime. Most paint evidence originates from crimes involving hit-and-runs. With a control sample to compare a suspected sample, paint can be matched to a vehicle with near 100% certainty. Blood, Semen, Saliva, Organs, and other Physiological Fluids. All body fluids, animal or human, will be subjected to biochemical analysis for determination of identity and origin. By examining the amount, color, and distribution of such fluids, an investigator may able to make several predictions about what took place at a scene. Blood, Semen, Saliva, Organs, and other Physiological Fluids. All body fluids, animal or human, will be subjected to biochemical analysis for determination of identity and origin. By examining the amount, color, and distribution of such fluids, an investigator may able to make several predictions about what took place at a scene.

49. Collecting Evidence Bag & Tag evidence according to standard operating procedures College class example video College class example video bsapp.com

50. Collecting Controls Controls are samples that help eliminate the innocent bystanders and those not considered as suspects. They include fingerprints, DNA Samples, Hair, and other evidence from possible suspects or victims for comparison to evidence. Controls are samples that help eliminate the innocent bystanders and those not considered as suspects. They include fingerprints, DNA Samples, Hair, and other evidence from possible suspects or victims for comparison to evidence. bsapp.com

51. Changes at Death When a person dies their body starts cooling to ambient temperature at an average rate of 1.5 o F per hour. This is called Algor Mortis. This is important in determining the time of death to help analyze the people and circumstances of the death. When a person dies their body starts cooling to ambient temperature at an average rate of 1.5 o F per hour. This is called Algor Mortis. This is important in determining the time of death to help analyze the people and circumstances of the death. The core temperature is most commonly taken by putting a thermometer probe into the liver. The core temperature is most commonly taken by putting a thermometer probe into the liver.

52. Autopsy An Autopsy is an examination of a cadaver (dead body) in order to determine the cause of death or to study pathologic changes. Also called necropsy, postmortem, postmortem examination. Video

53. Changes at Death 1. 1. Rigor mortis is one of the recognizable signs of death, caused by chemical changes in the muscles after death, causing the limbs of the corpse to stiffen after death. 2. Livor mortis is a settling of the blood in the lower (dependent) portion of the body, causing a purplish red discoloration of the skin.

54. Search Warrants A search warrant is a court order issued by a magistrate, judge or Supreme Court official that authorizes law enforcement officers to conduct a search of a person, location, or vehicle for evidence of a crime and to confiscate evidence if it is found. A search warrant cannot be issued in aid of civil process. A search warrant is a court order issued by a magistrate, judge or Supreme Court official that authorizes law enforcement officers to conduct a search of a person, location, or vehicle for evidence of a crime and to confiscate evidence if it is found. A search warrant cannot be issued in aid of civil process.

55. When is a Warrant Required for Evidence Collection? The Fourth Amendment to the United States Constitution protects Americans from unreasonable searches by the government. That means that absent an emergency situation or other legal exception, a police officer must have a search warrant before conducting a search of your person or property. The Fourth Amendment to the United States Constitution protects Americans from unreasonable searches by the government. That means that absent an emergency situation or other legal exception, a police officer must have a search warrant before conducting a search of your person or property.

56. How to Get a Warrant? A judge will only approve a search warrant if law enforcement is specific as to the items and location it wishes to search. Law enforcement must also prove that probable cause exists that a specific item is located in a specific place. A judge will only approve a search warrant if law enforcement is specific as to the items and location it wishes to search. Law enforcement must also prove that probable cause exists that a specific item is located in a specific place. Whether the warrant gets issued or not is up to the judge's review. If a judge finds that law enforcement has met its burden of probable cause and has included enough specificity in the request for the warrant, then the judge will issue the search warrant. Whether the warrant gets issued or not is up to the judge's review. If a judge finds that law enforcement has met its burden of probable cause and has included enough specificity in the request for the warrant, then the judge will issue the search warrant.

57. When is Search Warrant NOT Necessary? Consent: Law enforcement can request to enter a person’s home or search a person’s belongings Plain View Doctrine: Law enforcement does not need a search warrant to obtain evidence that is in plain sight. Emergency Situation: If the police are in hot pursuit of a felon and follow that alleged felon into a home or other private area then they do not need a warrant to obtain evidence that is in plain sight when they enter the building. Search Incident to Arrest: Police officers may search the body and immediate surroundings of a person whom they take into custody.

58. Review of the Crime Scene Analysis Video Video Video