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CHAPTER 5 (p.79) THE CRIME SCENE FOCUS. INTRODUCTION CRIME SCENE- A location at which a suspected criminal offense has occurred Processing the crime scene.

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Presentation on theme: "CHAPTER 5 (p.79) THE CRIME SCENE FOCUS. INTRODUCTION CRIME SCENE- A location at which a suspected criminal offense has occurred Processing the crime scene."— Presentation transcript:

1 CHAPTER 5 (p.79) THE CRIME SCENE FOCUS

2 INTRODUCTION CRIME SCENE- A location at which a suspected criminal offense has occurred Processing the crime scene is one of the most important parts of criminal investigation. Crime scenes contain physical evidence. Locard’s Transfer of Evidence theory- Entry brings evidence exit takes evidence.

3 CRIME SCENE Early investigators relied upon interrogations. Confessions are less important today. Confessions must be corroborated by physical evidence. Even eyewitness testimony is very inaccurate.

4 CRIME SCENE (Cont.) Accurate observation and recording is essential. Seemingly unimportant evidence may have great evidence in the investigation and trial.

5 EVIDENCE All evidence should be collected and processes with equal competency and thoroughness. Protect the crime scene- contamination- Remember Locard’s theory. Searching and recording- thoroughly Collection- Get all evidence- transport right Transportation- CHAIN OF CUSTODY

6 CHAIN OF CUSTODY Appoint one officer as evidence custodian. Everyone search, but ONLY one collects. You must document EVERY time evidence changes hands Breaks in the “Chain of Custody” will cause challenges in Motions to Suppress.

7 RECONSTRUCTION Investigator must reconstruct what happened at the crime scene. Crime scene types –Indoor –Outdoor World Trade Center Bombing 1400 vehicles processed

8 CRIME SCENE May be both indoor and outdoor Abduction of victim from home. Victim taken to wooded area Crime scenes may be multiple with multiple offenses.

9 RESPONSE TIME RESPONSE TIME- important that the first officer get to the scene as rapidly as possible. PROTECT THE CRIME SCENE Crime scene may become contaminated. Remember Locard’s principle. Theory of Transfer) Police officers are the worst offenders.

10 RECORDING THE SCENE Crime scene photos Coordinated photo series Objectively record the scene Photographic distortion

11 DIGITAL PHOTOGRAPHY Somewhat suspect because it can be altered- Defense atty. May attack its use. Take hundreds of photos and then transfer to a file for use of investigators Very good quality pictures Start close-up then move out. Measurement marker Record identifications on photos

12 IDENTIFICATION DATA 1. Subject 2. Location 3. Photographer 4. Case number 5. Time of dat- to the minute 6. Date of photograph 7. Photo series number 8. Weather, equipment, shutter speed

13 CRIME SCENE SKETCH See page 85- 86 in text. Rectangular Coordinate Method- straight line. Triangulation- measure from two fixed points. Projection- exploded sketch

14 CRIME SCENE SKETCH Must be accurate- re-measure Use pencil for rough sketch Final drawing in permanent ink Electronic systems are available

15 SKETCH REQUIREMENTS 1. Investigator name and identification 2. Location- City, State, Street address, Room location 3. Date and time of rough sketch 4. Evidence listing- Location by number 5. Case number 6. Directional arrow (compass heading) 7. Note “Not to Scale” or show scale

16 SEARCHING THE CRIME SCENE Primary reason- locate evidence Contamination Train officers Record name of everyone on scene- time of entry, reason for being there, time left Public expectations- crime shows distort

17 SEARCH METHODS See page 91 in text. STRIP SEARCH METHOD SPIRAL SEARCH METHOD SECTOR SEARCH METHOD GRID SEARCH METHOD

18 PHYSICAL EVIDENCE Record the location and photograph before collection- Record the: 1. Time and date 2.Location of discovery 3. Investigator and identification info 4. Item description 5. Identifying marks on items 6. Names of witnesses to finding evidence

19 EVIDENCE RECOVERY 1. Suspect identification 2. Establish offender’s MO 3. Proving or disproving an alibi 4. Connecting or eliminating suspects 5. Identify stolen items or contraband 6. Victim identification 7. Provision of investigative leads 8. Proving a statutory element of the crime

20 CHAIN OF CUSTODY (Cont.) EVERY TIME an item of evidence is moved the transaction must be recorded on the evidence sheet. Record on individual package when found Record all items on an evidence sheet –Lists items, dates, locations, and responsible persons –Initiate when found, update when placed in evidence room, each time it is moved

21 EVIDENCE COLLECTION TWO STAGE SEARCH- Large and small items- care not to contaminate trace evidence- handle as little as possible Obliterating fingerprints Leaving officers’ own fingerprints Fibers, hairs, liquids, bodily fluids Use tweezers, forceps May use special vacuum cleaner

22 CRIME SCENE RESOURCES GBI ASSISTANCE IS GREAT Trained in crime scene processing Competent in forensic evidence Has tools and test equipment Can focus only on your crime scene Stay until processing is complete Testify in court- Chain of Custody

23 MARKING EVIDENCE The types of mark of an item depends on: 1. Size of the object 2. Physical nature (solid or liquid) 3. Value of the object 4. Number of like objects

24 PACKAGING EVIDENCE 1. Package items separately. 2. Use clean packaging. 3. Use evidence tape to seal packages 4. Don’t fold cloth items unnecessarily 5. Don’t remove from container if possible 6. Use crime lab request for lab work 7. Send evidence in registered mail RRR

25 PACKAGING (Cont.) Organic items- (marijuana)- package in paper evidence bags- putrefaction- lose THC Other un-refrigerated items- (dry items) package in plastic evidence bags Refrigerated items- (blood) package in vials- vials in plastic evidence bags

26 THC TETRAHYDROCANNABINOL The illegal substance in marijuana

27 EVIDENCE STAGING STAGING- Attempt to redirect the investigation away from the logical truth Protect victim or family Conceal another crime- arson, fake burglary, sex crime stigma

28 EQUIVOCAL SCENES EQUIVOCAL SCENES- Open to interpretation Knife in chest may indicate suicide, accident, or homicide –Knife in chest is physical evidence- circumstantial because it does not prove who did it, only who was there when the victim was stabbed

29 PERSONATION PROFILING!! Offenders reflect their own personality traits in crimes they commit. –Remove only certain items –Position the body –Punish corpse after death –Suspect imparts identifying meaning – SIGNATURE ACTIONS

30 CRIME SCENE EQUIPMENT See p.98 for list of items

31 SPECIALIZED CSI 1. All Investigators are trained as CSI but depending upon their agency training is varied. 2. Half PD in country have <10 employees 3. CSI Crime shows are unrealistic- cause overoptimistic expectations.

32 EFFECT ON PUBLIC/ JURIES CSI Effect causes public to expect DNA, fingerprints, firearms testing, hairs, fibers and other TV activity. Absence of CSI info may mean acquittal Most Criminalists work in the laboratory, not on crime scenes. DON’T WATCH CRIME SHOWS- THEY ARE BAD FOR YOU!!!

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