Zoebella
Hollingsworth
Pearson betc level 3 national diploma in forensic and criminal investigation
Assignment 4 Unit A
P1: Describe the procedures used to preserve, collect, and record forensic evidence.
o Restriction of access.
When as the scene, the officers and CSIs should make sure that it has been properly
secured by putting:
- Police tape, this comes in handy as the tape can act as a barrier to the public,
keeping them out of the scene, to stop contamination.
- Police cars, can be used to block off different parts of the road if there has been
an accident on in.
- Police officers, they are usually stationed around the crime scene to prevent any
untheorized personal from getting on the scene.
- Forensic tents, these are usually used when there could be possible interference
from outside forces, like the weather, contaminating the evidence.
- Cordon logs are used to record/account for all the personnel attending the scene,
this is to them single out if there are any unauthorized personal on the scene,
possibly contaminating any evidence, or find any foreign DNA at the scene.
o Observation and recording, identifying and targeting evidence.
There are three possible observational techniques that could be used when investigating
a crime scene:
- Crime scene notes, the investigators should first identify the person who
contacted the police, then determine the time of contact and arrival at the scene.
They should then find out the preliminary case information and notes should be
made throughout the investigation, noting down any observations.
- Crime scene videography/photography, when photographing or videoing the
scene, there are three steps that are usually followed, these are a long view
(referred to as an establishing shot), then a medium view (which focuses on
specific objects, areas or evidence), and lastly a close- up (which shows the clear
condition and position of object at the scene). at the scene, the investigators
should use rulers and markers to identify areas/items the need to be
photographed.
- Sketches, these should be drawn on approved agency forms or graph paper. They
should be drawn to the scale ratio on the diagram or ‘no scale’ if none is used.
The sketch should contain; the case number, the date, investigators name/initial,
page numbering, arrows or indicators showing the north direction (relative to the
scene diagram) and the incident location address.
o Search patterns.
There are five possible crime scene search patterns that the investigator could use when
investigating a scene, they are:
, 1) Qudrat (Zone each pattern)- the crime scene is divided into smaller sections; one
or more investigators are assigned to search each zone.
2) Lane (line/strip search) - one or two investigators start at the boundary of the
scene and search in straight lines across to the other side
3) Grid search pattern – two or more investigators form a gird by searching in line
patterns the overlap and are perpendicular to each other.
4) Spiral search pattern – one investigator searches in a spiral pattern from the
centre of the scene to the boundary or vice versa.
5) Wheel search pattern – several investigators search in straight lines from centre
to the boundary or from the boundary to the centre.
o Limiting contamination.
- Contamination means the unwanted transfer of materials possibly from outside
the scene or between the evidence.
- It can be prevented by restricting access to the scene by limiting only essential
personnel to the scene.
How evidence might be contaminated. How this can be prevented.
SOCOs fingerprints, footprints, hair, fibres, Wear full protective gear: SOCO suits,
or DNA. gloves, mask, overshoes. No food,
drinks, or personal items at the scene.
Unsealed packages. Choose the correct type of packaging and
seal properly.
Two items of evidence in a single bag. Pack items of evidence into separate
