And Voice Analysis
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.
Select one of the topics below for more information:
use of handwriting analysis
|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.
Use of Handwriting Analysis
|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.
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.
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
| 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 printesd 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
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
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.