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| Handwriting
and Voice Evidence |
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Every person's style of handwriting is unique and
has its own personalised touch. It is because of this reason that
handwriting is very difficult to disguise and forge, making handwriting
analysis an effective tool for incriminating a suspect.
Voice analysis is also a helpful way of identifying
a criminal. Phonetics experts are able tell from a voice
what age, race and sex the person is, as well as trace phone calls
back to a particular caller.
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Select one of the topics below for more information:
--> Handwriting
--> The
use of handwriting analysis
--> Writing
comparison
--> Techniques
--> Analysing
print
--> Voice
analysis
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| Handwriting |
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| The
writing practices we learn during our time at school are very
difficult to lose, as we get used to the particular way that
we hold a pen, shape the letters we write and how we space our
words and lines. These are some of the factors that prove useful
during the analysis of a document. Investigators analyse these
aspects of suspicious documents i.e the printing style, paper
and ink, all of which help to identify a forged letter. |
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Writing samples are collected from everyday pieces of material.
Photo courtesy of www.morguefile.com.
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| The
Use of Handwriting Analysis |
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| The handwriting section of forensic
science involves the comparing and authentication of written documents
such as ransom notes, forged contracts, forged wills, fake
ID's and passports and any other form of writing or printed material.
The analysis of someone's handwriting is most commonly used to prove
that two documents were written by the same person. When looking at
a person's handwriting, the examiners usually look for personalised
characteristics under four areas including line quality, form, content
and arrangement. |
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| Writing
Comparison |
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The form of writing involves examining
the shape of singular letters and identifying if the slant
is in a certain direction, the size and how they are connected
with the next letter. Unusual characteristics, such as the
use of a plus sign or the ampersand (&) are also noted.
Examining the content of written and printed papers is done
to identify similarities between punctuation, spelling, grammar,
vocabulary and paragraph phrasing.
Document examiners compare unidentified
documents with a 'standard', a sample from a suspect. A standard
is usually produced by the suspect under supervision. Even
under supervision, the suspect still has the chance to disguise
their handwriting, which is why investigators then have to
collect other standards of casual handwriting from a suspect.
The casual handwriting is undisguised and can therefore be
compared with the unknown sample either with words that match
or letter-by-letter.
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Handwriting can be both manually examined, as well as using
the computer. Photo courtesy of Californian
Association of Criminalists. |
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| Techniques |
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| Initially, comparisons
are done with the naked eye or with a hand held lens, however,
the methods used today are by far more accurate. Special lighting
can help to reveal small, but useful details about how a document
was altered or created. Angled lights identify indents on the
paper, which suggests that a signature was traced and also shows the
roughness left on the paper after an eraser has been used. Backlighting
makes areas where an eraser has been used, turn lighter and makes
correction fluids dark. Examination using an infrared spectroscope
can identify if ink, that appears the same colour, is actually from
a different source by giving each colour a different cipher. |
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| Analysing
Print |
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| Faxed,
typed, printed and photocopied papers can also be analysed.
A typewriter whose letters have been worn down can identify
a specific machine the criminal used. A laser printer accumulates
small marks on its light sensitive drum that appear on every
printed document as minute black dots and photocopiers also
replicate these marks, as well as any dirt on the document or
the copier's glass. The header on a fax document also contains
details of the machine it came from and the machine it is going
to. If the information in the header is forged or changed in
any way, an analysis of the writing can reveal what make and
model the machine is. The composition of the ink, paper, glue
or fastenings can be used when comparing a number of documents
and dating the document. |
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Differing fonts and specific print patterns can identify a printer
or typewriter. Photo courtesy of www.morguefile.com.
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| Voice
Analysis |
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| Forensic phoneticians
specialise in language and speech science and have been used to solve
criminal cases. Phoneticians can deduce the age, sex and race just
from listening to their voice, particularly accents and digitalized
voices. These techniques are useful when listening to recorded phone
calls and voice messages. A technique known as voice spectrography
was invented in the 1960's and involves a program making a graphic
representation of sound. This particular graphing system measures
the amplitude and strength of sound in a person's voice. A
linear line cutting horizontally across a spectrograph represents
atmospheric pressure and the movement of the graph above and below
this line represents an increase/decrease of pressure due to speech.
Experts in this field are also able to identify different background
noises, enabling them to guess where the criminal may have been at
the time of the call. |
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