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| Recording
The Incident |
| After the crime scene
has been managed and the initial assessment (recording the original
situation and how it was discovered) is complete, the forensic photographers
arrive on the scene. The jury cannot revisit the scene of a crime
during court sessions, so photographs can help to vividly recreate
the scene as well as create a lasting record of the evidence so it
can be properly analysed in a forensic laboratory. |
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| Recording |
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| Where memory fails, technology has
replaced it, just as crime scene photography and videoing have replaced
baisc memory-based recounts of a crime scene with vivid live shots
of the aftermath.Through this, accuracy is greatly improved and the
film itself becomes a form of evidence. |
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| The
Camera |
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| Forensic photographers usually prefer
to use 35 mm cameras, or medium format, as it tends to balance the
portability and ease of use with quality images. When taking close-up
photos of evidence, the camera is often mounted onto a tripod for
stability to ensure the necessary quality required of photographs
presented as evidence in court. Some forensic labs have their own
darkroom facilities, which then enable photographers to develop the
pictures themselves. |
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| Digital
Cameras |
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Digital cameras have
a number of advantages when used in forensic photography as
they require no chemical processing, can be displayed on the
camera straight after being taken to ensure that the image was
captured and the photos can be immediately transferred to a
computer and stored in the database. However, digital photos
are very easy to alter which therefore prevents them from being
used as evidence in court. |
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Crime scene photography ensures proper documentation of the
crime sccene. Photo courtesy of www.imageafter.com.
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| Video
Cameras |
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| Video cameras also provide an easy
and inexpensive way to document crime scenes and can give the jury
with a more realistic sense of the crime scene than still pictures
of a room. The zoom on video cameras are however,more often digital
rather than optical and thus provide pictures of slightly less
clarity than actual photographs. Videos are in general a good briefing
tool for police officers who have not visited the crime scene. |
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| Techniques |
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| Close-up
shots of evidence have precise requirements, such as exactness, angle
taken and balance, in order to achieve the best possible shots. These
pictures of evidence form a factual record and must be able to be
reproduced in terms of size, shape and colour, thus, balance and accuracy
is an absolute must. The use of basic camera flash and flood lights
are quite sufficient for general crime scene photography, but close-up
shots of evidence require careful lighting. Artificial sources of
light have proved very useful in the photography of evidence. An example
of this concerns oblique-angled light, whereby the light is angled
or slanted towards the subject. This is used for bringing out the
detail in textured surfaces, such as foot and shoe prints left in
mud. |
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Above is a photograph of fibre under ultrviolet lighting. Photo courtesy
of Westchester
County NY Forensic Science Lab. |
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| Light |
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With
the help of coloured filters and adaptable light-guides, lamps can
direct a narrow beam of light at the subject of the photograph to
enhance the object details. Different light filters also allow for
the exposure of distinct evidence. For example, ultraviolet
light can make stains and fingerprints glow, violet makes gunshot
residue and blood more visible and blue and green lights are used
with enhanced fingerprints to show up fibres and urine. This is because
some materials absorb the ultraviolet light, while others reflect
it, causing the material to become present under the ultraviolet light
and flash of the camera when the photo is taken.
A crime scene is also documented by writing down
what the scene was like upon discovery, sketching, videoing, evidence
tables to document artifacts found, voice recording and witness
interviews.
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| *The
left image of the above photograph shows gunshot residue enhanced
by infrared lighting conditions, while the right is per normal. Photo
courtesy of Westchester
County NY Forensic Science Lab. |
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