Chapter 8 – Crime and Criminal Law Unit 3 – Criminal Law Crime Scene Investigation

  • View
    214

  • Download
    0

Embed Size (px)

Text of Chapter 8 – Crime and Criminal Law Unit 3 – Criminal Law Crime...

  • Slide 1

Chapter 8 Crime and Criminal Law Unit 3 Criminal Law Crime Scene Investigation Slide 2 Learning Goal for Today By the end of the lesson(s), students will be able to discuss police investigative and evidence gathering techniques By the end of the lesson(s), students will be able to discuss police investigative and evidence gathering techniques Slide 3 Expectations Expectations By the end of this lesson, students will: By the end of this lesson, students will: explain the processes of police investigation, arrest, search, and interrogation of suspects Slide 4 Agenda Crime Scene Investigation Crime Scene Investigation Fingerprints Fingerprints Trace Elements Trace Elements Gunshot Residue Gunshot Residue DNA DNA Slide 5 Introduction Chain of events from crime to trial is subject to the laws of criminal procedure Chain of events from crime to trial is subject to the laws of criminal procedure Laws balance two sometimes conflicting objectives: to discover the truth about a criminal event and to protect civil liberties Laws balance two sometimes conflicting objectives: to discover the truth about a criminal event and to protect civil liberties Rules of criminal procedure mark the boundary between legitimate police investigative practices and a persons right to liberty, privacy and personal security Rules of criminal procedure mark the boundary between legitimate police investigative practices and a persons right to liberty, privacy and personal security Slide 6 Introduction (Contd) Reflect the belief that state power should be limited Reflect the belief that state power should be limited That the rule of law applies as much to police as to people accused of crimes That the rule of law applies as much to police as to people accused of crimes That the ends do not always justify the means That the ends do not always justify the means Charter of Rights and Freedoms confirms our commitment to fair process making criminal procedure a matter of constitutional law Charter of Rights and Freedoms confirms our commitment to fair process making criminal procedure a matter of constitutional law Slide 7 Crime Scene Investigation Investigation and evidence collection and securing of evidence huge responsibility Investigation and evidence collection and securing of evidence huge responsibility Lapses can derail a trial or result in a miscarriage of justice Lapses can derail a trial or result in a miscarriage of justice Crime scene is a rich source of evidence Crime scene is a rich source of evidence Crime scene has boundaries Crime scene has boundaries Accidental contamination is an concern Accidental contamination is an concern Slide 8 Crime Scene Protect the area from accidental or intentional contamination by anyone, including police officers and other official personnel Protect the area from accidental or intentional contamination by anyone, including police officers and other official personnel s.129 of the Code, obstructing a police officer in the lawful execution of his/her duties; gives police authority to cordon off and refuse entry to a crime scene s.129 of the Code, obstructing a police officer in the lawful execution of his/her duties; gives police authority to cordon off and refuse entry to a crime scene Slide 9 Crime Scene Investigation Officer in charge of investigation determines when crime scene may be safely returned to public access Officer in charge of investigation determines when crime scene may be safely returned to public access Slide 10 Crime Scene Investigation Security of the scene falls under the coroners authority in the following cases: Security of the scene falls under the coroners authority in the following cases: Sudden or unexpected deaths Sudden or unexpected deaths Deaths of person in custody Deaths of person in custody Deaths occurring in institutions, aged Deaths occurring in institutions, aged Deaths from violence Deaths from violence Suicides Suicides Deaths occurring in a suspicious, unusual, or unnatural manner Deaths occurring in a suspicious, unusual, or unnatural manner Slide 11 Crime Scene Investigation Police officers may seize anything relevant to the investigation at the crime scene and to maintain the security of the scene until it is ordered released by the coroner following the post mortem examination Police officers may seize anything relevant to the investigation at the crime scene and to maintain the security of the scene until it is ordered released by the coroner following the post mortem examination Slide 12 Processing the Crime Scene Focus of police investigation is the collection of physical evidence Focus of police investigation is the collection of physical evidence CSI (Crime Scene Investigation) carried out by a mobile crime lab CSI (Crime Scene Investigation) carried out by a mobile crime lab Police prepare a description of what they find Police prepare a description of what they find Police photograph a scene Police photograph a scene Police prepare diagrams of sketches Police prepare diagrams of sketches Police collect evidence Police collect evidence Slide 13 Crime Scene Procedure Important to safeguard the continuity of evidence: Important to safeguard the continuity of evidence: No exhibit is left unattended from the time of its seizure until it is deposited in the police property stage facility No exhibit is left unattended from the time of its seizure until it is deposited in the police property stage facility The officer who seized the item, or the case officer, must secure the evidence in the police property locker, which is under the control of the property clerk The officer who seized the item, or the case officer, must secure the evidence in the police property locker, which is under the control of the property clerk Slide 14 Crime Scene Procedure The transfer of any evidence to the forensic laboratory is the responsibility of the case officer and/or his or her designate The transfer of any evidence to the forensic laboratory is the responsibility of the case officer and/or his or her designate The transfer of evidence to and from court is the responsibility of the case officer The transfer of evidence to and from court is the responsibility of the case officer No exhibit can be removed from the control of the property clerk without the appropriate authority and signature No exhibit can be removed from the control of the property clerk without the appropriate authority and signature The case officer is the officer in charge of the investigation The case officer is the officer in charge of the investigation Slide 15 Processing Physical Evidence Forensic scientists job is to put the evidence together correctly like the pieces of a puzzle Forensic scientists job is to put the evidence together correctly like the pieces of a puzzle Analysis of the evidence may involve biology, chemistry, physics, anthropology, geology, and computer science Analysis of the evidence may involve biology, chemistry, physics, anthropology, geology, and computer science Often called on to give expert testimony in court Often called on to give expert testimony in court Slide 16 Humour Break Slide 17 Some Pictures Made with Fingerprints Slide 18 Fingerprints Along with DNA, fingerprints are considered by many to be the best way to identify a suspect Along with DNA, fingerprints are considered by many to be the best way to identify a suspect Fingerprints never change and are unique to each person Fingerprints never change and are unique to each person Fingerprint patterns can be identified as one of three types: Fingerprint patterns can be identified as one of three types: Slide 19 Fingerprints 1. Arches, forming ridges that run from one side of the print to the other and curve up the middle 1. Arches, forming ridges that run from one side of the print to the other and curve up the middle 2. Loops, showing stronger curves than arches with ends that start on one side of the finger, loop around, and end up in the same place 2. Loops, showing stronger curves than arches with ends that start on one side of the finger, loop around, and end up in the same place 3. Whorls, forming complete ovals, often in a spiral pattern around a central point 3. Whorls, forming complete ovals, often in a spiral pattern around a central point Slide 20 Fingerprint Patterns Slide 21 Latent Fingerprints Created when a persons fingers come into contact with an object such a piece of glass or of plastic Created when a persons fingers come into contact with an object such a piece of glass or of plastic Created by a residue of oil and perspiration from the fingertip Created by a residue of oil and perspiration from the fingertip Usually invisible and requires the application of chemicals or laser light Usually invisible and requires the application of chemicals or laser light Slide 22 Visible Impressions or Fingerprints Result of a fingers contact where blood, dust or grease has been previously deposited Result of a fingers contact where blood, dust or grease has been previously deposited Slide 23 Fingerprints Moulded fingerprints: Moulded fingerprints: Leaves a visible impression in a soft substance such as clay, wax or putty Leaves a visible impression in a soft substance such as clay, wax or putty Slide 24 Fingerprints Processing Fingerprints taken from crime scene are sent to a central repository administered by the RCMP in Ottawa Fingerprints taken from crime scene are sent to a central repository administered by the RCMP in Ottawa If the quality of the fingerprint is adequate (20% of a print) and the individuals prints are on file as a result of previous arrest or conviction the individuals identity can be determined through comparison If the quality of the fingerprint is adequate (20% of a print) and the individuals prints are on file as a result of previous arrest or conviction the individuals identity can be determined through comparison Slide 25 F