Title: Fingerprinting
1ASISTM ProjectForensic Investigations
2What are fingerprints?
- On the fingers and palms of the hands and the
toes and soles of the feet the skin is covered
with friction ridges.
3Photograph Paul Ricketts, 2006
4Why do we have friction ridges?
- Friction ridges are used to increase grip and the
sense of touch.
5Photograph Paul Ricketts, 2006
6Friction ridges on the feet
Photograph Paul Ricketts, 2006
7Friction Ridge Patterns
- There are 3 main friction ridge patterns
- Loops - most common
- Whorls
- Arches - least common
8Loop
Image courtesy J. Dook, 2006
9Whorl
Image courtesy R. Henderson, 2006
10Arch
Image courtesy J. Dook, 2006
11Minutiae - fine detail
Image courtesy R. Henderson, 2006
12Minutiae Patterns
Image courtesy J. Dook, 2006
13Example
Image courtesy J. Dook, 2006
14Sweat Pores
- It is possible to see small white dots on the
friction ridges - the white dots are sweat pores.
15Sweat pores
Image courtesy C. Henderson, 2006
16Identical Fingerprints?
- No two fingers have ever been found to possess
completely identical friction ridge patterns.
17Twins
CH Left middle finger
RH Left middle finger
The boys both have a LOOP pattern but one of the
twins appears to have cut his finger at some
stage.
Image courtesy R. Henderson C. Henderson, 2006
18Twins Fingerprints
- The minutiae or fine details of identical twins
fingerprints are different.
19Twins - minutiae
Image courtesy R. Henderson C. Henderson, 2006
RH Left middle finger
CH Left middle finger
20How to take a fingerprint
- An easy way is to use a pencil
- 1) Rub an area on a piece of paper with a
pencil. - 2) Then rub your finger over the graphite on the
paper. - Next, apply a small piece of sticky tape to the
finger, lift and place the tape on the sheet of
paper. - Make sure you clearly indicate from which finger
the sample is from.
21An easy way to take a fingerprint
Photograph Paul Ricketts, 2006
22An easy way to take a fingerprint -2
Photograph Paul Ricketts, 2006
23An easy way to take a fingerprint -3
Photograph Paul Ricketts, 2006
24Brushing for a fingerprint at a crime scene
Image courtesy J.Dook, 2006
25Finding Fingerprints
- Some fingerprints are obvious - these are called
visible prints.
26Visible fingerprints on a door
Photograph Paul Ricketts, 2006
27Finding Fingerprints
- Some fingerprints are NOT obvious - these are
called latent prints.
28How do you find latent prints?
- Certain chemicals attach to substances that have
been excreted by the sweat pores.
29Using superglue
30Using iodine
31Using ninhydrin
32References
- Images
- Fingerprints of J. Dook, R. Henderson and C.
Henderson were taken using a pencil as described
on Slide 17. The prints were then scanned into
Adobe Photoshop at a resolution of 1200dpi. - J. Dook is the hand and foot model.
- Slide 18 image taken of Police Constable Darren
Fisher by J. Dook at the Joondalup Police
Academy, November 2005. - All other photography by Paul Ricketts, DUIT
Multimedia, the University of Western Australia. - Graphic design of slides by Trevor Hutchison,
DUIT Multimedia, the University of Western
Australia.