Dactyloscopy project - ecrimescenechemistrymiller
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Transcript Dactyloscopy project - ecrimescenechemistrymiller
Dactyloscopy
(the study of fingerprints)
By: Aidan Smith
Types of Fingerprints
• There are three different types of Fingerprints
• Loops
• Arches
• Whorls
Loops
• Loops are the most common making up about 60 to
about 70 percent of all fingerprints
• They come in from the sides of the finger and loop
around in the middle of the finger and go out the
same side it came in
• Usually have one delta
Picture of a Looped
Fingerprint
Whorls
• Whorls make up about 25 to 35 percent of all
fingerprints
• Usually have their own circle(s)
• Two deltas classify a Whorl
• Many types of Whorls
• Plain, accidental, pocket Whorls
Picture of Whorl
Arches
• Make up about 5 percent of all Fingerprints
• There is no delta
• Ridges stretch across the finger
• Tented Arches look like it could be a delta
Pictures of an Arch and
Tented Arch
Regular Arch
Tented Arch
Types of Prints
• Three different ways to have a fingerprint
• Latent
• Patent
• Plastic
Latent Prints
• Latent prints are probably the most common type of
print to find
• These prints are invisible to the human eye without a
black light or “dusting”
• Fingerprints leave behind residue (sweat, oils) which
is only found with these tools
Patent Prints
• Visible to the human eye without the needs of any
special tools
• Usually photographed
Plastic Prints
• Easily findable
• Left in blood, melted wax, etc.
• Easily visible to human eye
• Photographed
Techniques
• Photographing
• Take pictures of the fingerprints and scan them into a
computer as well as chemically developing fingerprints,
put them on a contrasting background
• “Dusting”
• Involves brushing areas at a crime scene with chemicals
so that fingerprints will show up
• Picked up with clear tape and put on background so
they will contrast and are able to work with print
Education
• Usually need a college degree or equivelent (Biology
and Chemistry are good degrees)
• Need a couple years experience in the field. Many
learn as they work with older more experienced
experts
Carmine Artone
Retired Supervisor of US Secret Service, Identification Branch
• Started her career right out of high school, never went to
college. Never earned her degree.
• After working for the FBI she went to the Miami Dade
Police where she was trained in Latent fingerprint
identification
• Normal days consisted of examining crime scene prints
and comparing then to known criminals…very tedious
since the prints were never complete or clear
• Most Dactyloscopists don’t have another job
Carmine Atone…continued
• She testified in many court cases about the evidence
she found and many times her evidence
(fingerprints) were very important
• One case she remembers she was called to testify
and the prints she had found in blood on the victim’s
clothes were consistent with the killer’s prints
• Thus she helped convict the man for murder
Court Case 1911
•
Chicago, Illinois. December 21, 1911
•
Thomas Jennings tried for murder of Clarence Hiller who was
shot
•
Fingerprints were found in fresh paint left from a job earlier that
day. The fingerprints matched Jennings’s prints. Ballistics also
matched their test bullet to that of Jennings bullet at the crime
scene.
•
To be sure that the fingerprints were real and that it wasn’t
tampered evidence several experts were witnesses to the evidence
•
With the help of this evidence Jennings was convicted and hanged
on February 16, 1912
Bibliography
•
http://74.125.45.104/search?q=cache:XhZhwUKZ1jwJ:www.lakesidesch
ool.org/upperschool/departments/science/forensics/documents/CaseStu
dyFingerprints.doc+thomas+jennings+case&hl=en&ct=clnk&cd=2&gl=us
•
http://www.brazoria-county.com/sheriff/id/fingerprints/tarch.jpg
•
http://www.britannica.com/EBchecked/topic/149492/dactyloscopy
•
http://en.wikipedia.org/wiki/Fingerprint
•
http://www.forensic-science-info.com/images/whorl-fingerprint.jpg
•
http://www.fprints.nwlean.net/j.htm
•
http://www.mondovista.com/fingerprint2.jpg
Bibliography Con’t
• http://onin.com/fp/fpxperts.html
• http://www.policensw.com/info/fingerprints/finger07.ht
ml
• http://www.policensw.com/info/fingerprints/indexfinge
r.html
• http://www.policensw.com/info/fingerprints/images/pa
rcha.jpg
• http://ridgesandfurrows.homestead.com/science.html