Unit 23B assignment
Investigating a crime scene
P4 Describe the forensic methods used to process a simulated crime scene
Biological evidence= fingerprints, blood
Chemical evidence= Drug powder, gunshot residue
Physical evidence= Footprints, Document
How to photograph that piece of evidence
Fingerprints:
Place a white card behind the glass and use a low oblique angle of light to photograph fingerprints
on glass (windows, drinking glasses, etc.). They can also be shot by placing a diffused light source
behind the glass and employing transmitted lighting. If the fingerprint is not on glass, however, you
should set the transferred fingerprint on a black backdrop and take a vertical picture with the flash,
being sure to capture all of the fingerprint. Low light aids in obtaining the necessary contrast for a
good image.
Blood:
Colour print film and/or colour slide film can be used to photograph blood evidence. Bloodstains on
dark surfaces can also be recorded using infrared film. To acquire an accurate representation of the
blood spatter, the shot should be taken close up vertically using measures such as a ruler.
Drug Powder:
This is photographed at a right angle to eliminate any distortion; a ruler should be used to get an
accurate size and dimensions of the drugs.
Gunpowder residue:
Gunpowder residue should be photographed at a right angle to eliminate any distortion, it should
also be a ruler against the powder, so it gives an accurate representation of the size of the
gunpowder.
Footprints:
Use a scale against the impression to get an accurate representation of the size of the shoe and take
the picture vertical from the impression using the flash and get other angles and close ups of the
impression to highlight the details of the shoe.
Document:
Take the picture of the document vertical and use a scale to show the size of it, also you should take
photos of the documents after it has been moved to get the information on there.
Sketch of the evidence location included on crime scene sketch
,
,
Investigating a crime scene
P4 Describe the forensic methods used to process a simulated crime scene
Biological evidence= fingerprints, blood
Chemical evidence= Drug powder, gunshot residue
Physical evidence= Footprints, Document
How to photograph that piece of evidence
Fingerprints:
Place a white card behind the glass and use a low oblique angle of light to photograph fingerprints
on glass (windows, drinking glasses, etc.). They can also be shot by placing a diffused light source
behind the glass and employing transmitted lighting. If the fingerprint is not on glass, however, you
should set the transferred fingerprint on a black backdrop and take a vertical picture with the flash,
being sure to capture all of the fingerprint. Low light aids in obtaining the necessary contrast for a
good image.
Blood:
Colour print film and/or colour slide film can be used to photograph blood evidence. Bloodstains on
dark surfaces can also be recorded using infrared film. To acquire an accurate representation of the
blood spatter, the shot should be taken close up vertically using measures such as a ruler.
Drug Powder:
This is photographed at a right angle to eliminate any distortion; a ruler should be used to get an
accurate size and dimensions of the drugs.
Gunpowder residue:
Gunpowder residue should be photographed at a right angle to eliminate any distortion, it should
also be a ruler against the powder, so it gives an accurate representation of the size of the
gunpowder.
Footprints:
Use a scale against the impression to get an accurate representation of the size of the shoe and take
the picture vertical from the impression using the flash and get other angles and close ups of the
impression to highlight the details of the shoe.
Document:
Take the picture of the document vertical and use a scale to show the size of it, also you should take
photos of the documents after it has been moved to get the information on there.
Sketch of the evidence location included on crime scene sketch
,
,
