Presentation is loading. Please wait.

Presentation is loading. Please wait.

Field Survey & Burial Recovery Forensic Science I.

Similar presentations


Presentation on theme: "Field Survey & Burial Recovery Forensic Science I."— Presentation transcript:

1

2 Field Survey & Burial Recovery Forensic Science I

3 Part I: The Crime Scene: Discovery and Recovery

4 At the Crime Scene The first person on the crime scene is usually a police officer. Their first job is to: –Take care of emergencies. Get medical attention for any victims Disarm/arrest perpetrators.

5 Next, they secure and isolate the crime scene to prevent unauthorized access to the area: –Erect ropes or barricades –Position guards –Identify & Separate Witnesses

6

7 Crime Scene 5 6 7 8 Posted Sentry with Access roster Close two lanes of traffic, open other two, but make them 1 way Re-route parking lot cars & Students Take no more than 6 hours

8 Recording the Crime Scene Photograph the Scene Scene should be unaltered Entire area should be photographed, in addition to adjacent areas Many angles should be used

9 Recording the Crime Scene Photograph the Scene o Position and location of body and other evidence should be shown o Close-up pictures of injuries and weapons o Use a scale to show size of an object o Videotaping is another option

10

11

12

13

14 Recording the Crime Scene Sketching the Crime Scene  This is a rough sketch  Should show accurate measurements  Must show all relevant evidence  Has a legend below drawing  Should have compass heading designating north  A finished sketch can be done later (using CAD or other computer software)

15 To Sketch a Crime Scene: Observe and plan Avoid destruction of evidence Identify what is relevant Stand at doorway and start sketch there (if you’re indoors) Always search and sketch in the same way, to establish uniformity in procedure (for court testimony)

16 Measure distances & outline the area Measure from permanent, fixed objects Position sketch so North is at top Determine scale Use approximate shapes for sketching objects To Sketch a Crime Scene:

17

18

19 Detailed written description of the scene Location of items of evidence recovered Describe who discovered evidence, who packaged evidence, where evidence went once packaged Chain of Custody Recording the Crime Scene Taking Notes About the Crime Scene

20 Recording the Crime Scene Taking Notes About the Crime Scene  Used to “refresh” investigators’ memories – often years after the crime  Notes can be taped rather then written (they will have to be transcribed later)

21 Crime Scene Search –A systematic search for evidence must be planned and executed. –Types of search patterns –Spiral –Line or Transect –Grid method Evidence to be collected depends on the crime committed, including: Evidence a crime was committed Evidence of how the crime was committed Evidence of who committed the crime

22 Jessica Ridgeway murder search

23 Systematic Search Thorough & systematic No pertinent evidence overlooked! This insures factual & unbiased reconstruction Advisable to have one person supervising and coordinating the collection of the evidence Physical evidence can be anything from massive objects to microscopic traces

24 Collection and Packaging of Evidence –Avoid Contamination! –If possible evidence should be submitted intact (entire article of clothing, etc.) Hairs, fibers, blood should not be removed from clothing Trace evidence should be collected with forceps and placed in bottles, pillboxes, envelopes, or screw-cap glass vials. Bloodstained materials should NOT be stored in air-tight containers (mold) Items from the scene of a suspicious fire MUST be stored in air-tight containers.

25 Chain of Custody Every person who handled or examined evidence must be accounted for Everything must be carefully marked

26 Controls must be obtained –Samples to compare for comparison Test for Contamination Test for match (suspect)

27 Safety and Legal Issues Fear of AIDS, Hepatitis, other Pathogens –Latex gloves and protective shoe covers –Particle mask and goggles if dust present –Anything that comes into contact with potentially infectious materials (fingerprint brushes, gloves, pencils, etc.) should be placed into biohazard bag –No eating, drinking, or smoking at crime scene

28 Legal Search & Seizure Issues Fourth Amendment guarantees against unreasonable searches and seizure Need a Warrant to search, except: –Emergency circumstances –Need to prevent immediate loss or destruction of evidence –Search of a person lawfully arrested –Consent of parties involved

29 Part II How do we find buried remains?

30 Field Survey

31 Aerial Survey

32 Canine Survey

33 Remote Sensing Survey

34 Crime Scene Search Methods Linear (Strip) Grid Wheel Spiral Zone Link

35 Linkage Theory Crime Scene Evidence Victim Suspect

36 If all else fails, walk every inch of the ground – via Pedestrian Survey

37 Linear Transect Ground Survey

38 Find Evidence of Disturbance Isolate the Disturbance

39 Then, Excavate

40 Recovering the Remains You’ll need these tools: –Smooth tipped shovel; sharpened trowels; screen sifters; paint brushes; and buckets A meter grid is utilized for documentation Photographs should be taken as items are uncovered –Each bone, clothing item, etc. should be photographed in its original position

41 Recovering the Remains Vegetation and insects should be collected Remove dirt one grid at a time (10cm at a time) –Avoid the temptation to dig to the bottom of the grave Soil should be sifted to ensure that evidence is not missed –When something is found, it should be labeled with the grid number and depth –Provides a 3-D picture of where evidence was collected from

42 Recovering the Remains Size and depth of the grave can tell whether the grave digger was rushed Expose the entire skeleton, before you begin to pull bones or fragments out Fresh remains (fleshy) should be recovered in a body bag, or container

43 Recovering the Remains Damp clothing, wallets, etc. should be placed in brown paper bags and allowed to air dry Fully skeletonized remains should be bagged separately After the removal, search under the body –Bullets; gloves; guns; knives; etc. –Soil can contain important info! Insects, chemicals, etc.

44 Forensic Anthropology Anthropologists have the ability to: –Analyze human remains for clues as to age, sex, race, etc. –Recover burial remains in an efficient manner –Analyze the scene and gravesite for clues as to what occurred –Find relevant clues on bones and teeth to determine COD

45

46

47 QUESTIONS??????


Download ppt "Field Survey & Burial Recovery Forensic Science I."

Similar presentations


Ads by Google