Science of Crime Scenes Chapter 8.4 - PowerPoint Presentation

Slide1

Science of Crime Scenes

Chapter 8.4

Science of Crime Scenes

1

Slide2

Underwater and Underground Crime Scenes

Science of Crime Scenes

2

Slide3

Underwater and Underground Crime Scenes

underwater and underground crime scenes, due to their uncommon, if not evidence-hostile, conditions and the related dangers for the investigators

are special casesPreplanning, organization, and specialist teams are mandatory to collect and secure evidence and to be able to analyze them at the scene.

Because scenes like these are easily identified in advance and do not generally require immediate emergency response, preparations are relatively easy to do.

Science of Crime Scenes

3

Slide4

Science of Crime Scenes

4

Slide5

Underwater Scenes

Science of Crime Scenes

5

Slide6

Underwater scenes

Underwater scenes can be of various types and depth:

swamp, river (with or without currents),

quarry

,

lake

,

at

sea

Science of Crime Scenes

6

Slide7

Dangers

Dangers still exist for investigators working these crime scenes as cold, current, tide, swell, waves, visibility, and even animals can present hazards, to say nothing of the water itself

.Getting into the water can even be difficult because of impediments such as ice, flotsam, or pollutants on the

surface

Just like terrestrial scenes, each water crime scene will require a different approach to minimize the loss of evidence and to maximize information

Science of Crime Scenes

7

Slide8

Science of Crime Scenes

8

Slide9

Science of Crime Scenes

9

Slide10

Science of Crime Scenes

10

Slide11

Science of Crime Scenes

11

Slide12

Locating the Scene

The first, and sometimes greatest, challenge is to locate the area of interest or the evidence to collect

.Witness statements, water flow rates at various depths, wind direction, and speed are good starting points to improve the search efficiency

.

As a body decomposes, the gas generated by bacterial action fills the body cavity and will cause the remains to float for a period of

time.

Criminals may weight bodies to keep them underwater; depending on the method of weighting, this can be excellent evidence to help source the materials or identify the criminals

Science of Crime Scenes

12

Slide13

Science of Crime Scenes

13

Slide14

Body location

If the body is punctured by an object or animal activity, the body

will partially or completely submergeGrappling hooks should be used with great care when trying to pull a floating body in, as they can severely damage evidence and create false wounds that can complicate an

autopsy

Instead of immediately diving into the water and attempting to retrieve the remains, evidence detected on the surface should be located and marked either by a buoy or a Global positioning systems (GPS) recording device

Science of Crime Scenes

14

Slide15

Science of Crime Scenes

15

Slide16

Working the Scene

Once the surrounding area is searched, the perimeter can be identified and marked; a search grid has to be defined to ensure a full search of the entire perimeter

.This may be outlined by buoys on the surface or a physical grid can be placed underwater with precut PVC tubes of known length, filled with

sand

In case of low visibility, lines can be placed to help the divers move around the scene within each grid

.

Two

divers can then drag a rope over the search area to snag any protruding object.

Science of Crime Scenes

16

Slide17

Equipment

Besides the divers’ equipment, specialized forensic equipment and technology are necessary to lift evidence from its position and properly collect it

.one-use gloves should still be used underwater when sampling biological evidence to minimize

contamination

Waterproof cameras and video cameras with special lighting have to be used, if the water clarity allows it

.

Advanced diving robots can also be used to view the crime scene remotely, providing for viewing on the surface.

Science of Crime Scenes

17

Slide18

Preservation

Once located, photographed, and sketched, evidence would be transported to the surface and then to the laboratory in proper containers to preserve the consistency of the

evidenceItems that have been submerged for some time tend to deteriorate rapidly once removed from the water due to oxidation or damage from

salt

The best preservation method would be to package the evidence in a bucket or a container with the water in which the object was

located

This protocol is mandatory for ferrous evidence, such as tools or

firearms

An

immersed weapon could appear to be in good condition in the

water but

will start to rust as soon as it hits the air

Science of Crime Scenes

18

Slide19

Science of Crime Scenes

19

Slide20

Science of Crime Scenes

20

Slide21

Underground Scenes

Science of Crime Scenes

21

Slide22

Underground Scenes

Perhaps even more so than underwater scenes, underground scenes are difficult to enter and are not convenient for standard forensic investigations

.Darkness, fear of heights (acrophobia) or being enclosed (claustrophobia), and the dangers of tight spaces do not ease forensic work

Science of Crime Scenes

22

Slide23

Science of Crime Scenes

23

Slide24

Dangers

being trapped underground,

toxic gases, Fallingprotective gear

includes

helmet

,

gloves

,

pads

,

oxygen breather

rated climbing cords of 8–11 mm

Science of Crime Scenes

24

Slide25

CSI kits

Because of the difficulty to gain access to the crime scene, each CSI probably will be able to take only one crime scene kit each

.The kits should be compact, practical, and not jeopardize either the movement or the safety of the examiner when wearing one

Checklists are good ideas, as it may be difficult to backtrack to retrieve forgotten items once the CSIs are down at the scene

.

I

t

may not be possible to retrieve all of the available evidence from an underground scene and so it is even more important to clearly select only the most relevant and important evidence to collect and carry back to the surface.

Science of Crime Scenes

25

Slide26

Science of Crime Scenes

26

Slide27

Combinations

Disasters, like the wreck of the Costa

Concordia off the coast of Tuscany in 2012Need both underwater and climbing skills applied even though they are not technically “underground

.”

Such crime scenes require a long and exhausting approach to the crime scene that necessarily will limit the ability to manage the underwater crime scene.

Science of Crime Scenes

27

Slide28

Science of Crime Scenes

28

Slide29

Science of Crime Scenes

29