Even
with the recent advancements made in the field of DNA
analysis, the science of fingerprinting, dactylography,
is still commonly used as a form of identification,
whether it has been taken in the traditional way using
ink and paper or scanned into a computer database. Fingerprint
identification is based on the classification of fingerprint
patterns, which can not only prove that a person was
present at a crime scene, but can also be used to compare
with the stored fingerprints of millions of other known
criminals.
Sir Francis Galton was
one of the first to indulge himself into the possibilities
of using fingerprints as a form of identification. His
work in this field inspired the creation of an early
fingerprinting filing system, known as 'icnofalagometrico',
developed by an Argentinian police member, Vucetich,
whom had had correspondence with Sir Francis. The first
fingerprinting bureau was opened by Vucetich in 1892,
the same year Sir Francis released his works on fingerprinting.
In 1896,
an English fingerprint scientist by the name of Sir
Henry Edward, who was a pupil of Galton, created the
'ten print' system of classification, which became the
most commonly used technique until the introduction
of computers in the late 20th century. It was first
implemented in India in 1897 and had its own unique
way of classification. Edward divided the patterns in
fingerprints into two groups known as value patterns,
which contained whorls, and the no-value patterns, which
contained loops and arches.
*
Sir Edward is most noted for his contributions to the
science of fingerprinting. Photo courtesy of Northampshire
Police.
A fingerprint
that contains a whorl pattern was given a number value
that depended on which finger the print came from.
A thumb on the right hand containing a whorl is valued
with number 16, but the little finger on the left
hand containing a whorl was only given a value of
1. Edward then grouped together values from certain
fingers, forming a fraction-like code for each set
of ten fingerprints. Altogether, Edward created 1024
individual codes, his pioneering work ensured that
any set of prints could be filed using this code.
His system of fingerprint filing worked very well
in identifying criminals working under aliases.
Suspected
criminals were fingerprinted and coded before being
compared against known criminals stored under the
same code, making it much faster searching for a match
as investigators didn't have to search through the
entire collection. This system did however, have some
drawbacks, as a whole and complete set of ten fingerprints
was required, making it difficult to identify single
prints found at a crime scene. A single print identification
system was later developed in the 1930's allowing
the classification and filing of single prints from
individual fingers.
If the print has an
unusual shape or characteristic, it is easily and quickly
matched, but in most cases, fingerprints found at a
crime scene are rarely fully intact and therefore influences
the quality of the search. As time progressed, fingerprint
collections grew and the job of searching them became
more difficult and time consuming. Finally in the 1960's,
computer systems were introduced and constantly improved
until they were fast and efficient and able to be used
for public purposes.
The comparison of fingerprints
is a time consuming procedure and requires experience
and great skill. Examiners look at the shape of the
ridges
and compare the points where the ridges start, end,
join and split. The positions of short ridges, dots
and any enclosed areas are also noted. Examiners also
search for points of similarity between the fingerprint
mark and the print to try and decide if the two patterns
match.
The
computer systems used at present are able to scan
fingerprints that have been found at a crime scene
and automatically find and record the ridges,
whorls, arches or loops contained within. This
data is then compared by the computer with information
that is similar in the database and finally produces
a shortlist of matches in order of likeliness.
The crime scene fingerprint is compared manually
by investigators with the shortlist to identify
any matches.
*
The use of computers makes fingerprint comparing
much easier. Photo courtesy of www.greenvillecounty.org.
