FORENSIC SCIENCE Crime Scene Analysis

2 CRITICAL THINKING When Mrs. Jackson came back from lunch, there were several messages on her desk. By changing each digit of the phone numbers to one of the three corresponding letters on the telephone buttons, can you determine from whom each message came?

3 Answers to Critical Thinking â dentist â(222) accountant â printer â husband â airline â teacher

4 FACETS OF GUILT âMeans--the ability of have committed the crime âMotive--the reason for committing the crime. (This doesn’t have to be proven or presented in a court of law, but its what everyone wants to know.) âOpportunity--time or availability to have committed the crime.

5 Murder Charges *1st Degree Murder--premeditated *2nd Degree Murder--killed intentionally, but not thought out as much ahead of time *Voluntary Manslaughter--usually involves sudden passion (fear, rage, anger, terror) *Involuntary Manslaughter (criminally negligent homicide)--killed someone, but unintentionally

6 Crime Scene Team Is a group of professional investigators, each trained in a variety of special disciplines. Team Members ãFirst Police Officer on the scene ãField Evidence Technician ãMedical Examiner (if necessary)

7 First Officer at the Scene ãAAssess the crime scene ãDDetain the witness ãAArrest the perpetrator ãPProtect the crime scene ãTTake notes

8 Evidence Technician ãRecord the crime scene ãPhotography ãSketches ãNotes ãConduct a search for evidence ãSet up numbers at the pieces of evidence ãHas the necessary equipment ãForceps ãBags--paper and plastic ãEnvelopes ãJars and Q-tips ãProperly collect all evidence ãMaintain a chain of custody ãObtain reference samples (evidence whose origin is known) ãSubmit evidence to Lab

9 Medical Examiner’s Responsibilities (Review) ãIdentify the deceased ãEstablish the time and date of death ãDetermine a medical cause of death -- the injury or disease that resulted in the person dying ãDetermine the mechanism of death -- the physiological reason that the person died ãClassify the manner of death ãNatural ãAccidental ãSuicide ãHomicide ãUndetermined ãNotify the next of kin

10 Physical Evidence  All objects that can establish that a crime has been committed  Can potentially link a crime to a victim and/or a crime to a perpetrator  Can be anything from massive objects to microscopic traces

11 Evidence Characteristics Class Evidence--common to a group of objects or persons Individual Evidence--can be identified with a particular person or source. ABO Blood TypingBlood DNA Typing

12 Crime Scene Sketch Date: August 14, 2001Criminalist: Ann Wilson Time: 11:35Location: 4358 Rockledge Dr St. Louis, Mo. A. Couch/sofa B. Female body C. Knife D. Over turned Lamp E. Chairs F. Table G. Fireplace c D E E E E E A G F

13 Crime Scene Search Patterns  Spiral  Grid TWO of FOUR PATTERNS

14 Crime Scene Search Patterns  Strip or Line  Quadrant or Zone TWO of FOUR PATTERNS

15 Crime Scene Mapping (outdoors) âAzimuth--uses a compass beam to determine the location of each piece of evidence âTriangulation--uses two points at the crime scene to map each piece of evidence âCoordinate or grid--divides the crime scene into squares for mapping. âSuspended Polar Coordinate--for use in mapping evidence in a hole âBaseline--set a north/south line and measures each piece of evidence from this line.

16 AZIMUTH Determines: Direction Distance Elevation

17 TRIANGULATION Measure from A to B and then to the evidence in a triangular shape.

18 Coordinate or Grid Mapping Set a north/south line from a datum point established by a GPS. Make it a perfect square (4 x 4) by shooting the hypotenuse and setting in stakes every foot or meter. Measure and map the location of each piece of evidence. Then collect evidence and place in containers by grid.

19 Baseline Mapping Set a north/south line from the furthest most points of the crime scene. Then measure each piece of evidence from that baseline. Evidence will need a numerical measurement where the piece begins, ends and in the middle. Evidence Baseline

20 Suspended Polar Coordinate Measure and map each layer of evidence as you move down the hole. Use the compass readings from the top to measure degrees and a tank dipping line to measure depth.

21 MAPPING TECHNOLOGY The latest technology includes this Nikon Tsunami with computer. The exact location of all crime evidence can be determined and directly loaded into a computer to produce a crime scene map. Cost = $35,000 for the set.

22 Remember: “HOW PLUS WHY EQUALS WHO” --John Douglas, former FBI profiler Keep this in mind as you analyze a crime scene…