Handwriting Comparison
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Introduction
• Any object with handwriting or print whose
source or authenticity is in doubt may be referred
to as a questioned document.
• Document examiners apply knowledge gathered
through years of training and experience to
recognize and compare the individual
characteristics of questioned and known
authentic writings.
• For this purpose, the gathering of documents of
known authorship or origin is critical to the
outcome of the examination.
• The uniqueness of handwriting makes this type
of physical evidence one of the few definitive
individual characteristics available.
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Questioned Documents
 Identify a questioned document.
 Understand common individual
characteristics associated with handwriting.
 List important guidelines for collection of
known writings for comparison to questioned
documents.
 Have a general idea of techniques used to
uncover indented writings and pen inks.
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Questioned Documents
~Any object handwritten/typewritten or
computer generated whose source of
identity is in doubt.
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Letters
Checks
Drivers licenses
Contracts
Wills
Voter registrations
Passports
Petitions
Lottery tickets
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Character of Handwriting
• Document experts continually testify to the
fact that no two individuals write exactly alike.
• Many factors comprise the total character of a
person’s writing.
• The early stages of learning handwriting are
characterized by a conscious effort to copy
standard letter forms.
• However, as writing skills improve, nerve and
motor responses associated with the act of
writing become subconscious.
• The unconscious handwriting of two different
individuals can never be identical.
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Handwriting Analysis
• Graphologist – an expert in the field of
handwriting analysis
• Graphology – the study of a person’s
handwriting that allows the expert to
characterize personality traits and
psychological disposition.
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Character of Handwriting
• Variations are expected in angularity, slope,
speed, pressure, letter and word spacing, relative
dimensions of letters, connections, pen
movement, writing skill, and finger dexterity.
• Other factors to consider include the arrangement
of the writing on the paper, such as margins,
spacing, crowding, insertions, and alignment.
• Spelling, punctuation, phraseology, and grammar
can be personal and help to individualize the
writer.
• Furthermore, the writing style of one individual
may be altered beyond recognition by the
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influence of drugs or alcohol.
Character of Handwriting
• No single handwriting characteristic can in
itself be taken as the basis for a positive
comparison.
• The final conclusion must be based on a
sufficient number of common characteristics
between the known and questioned writing
samples.
• There are no hard and fast rules for a
sufficient number of personal characteristics;
it is a judgment call made by the expert
examiner in the context of each case.
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Handwriting Characteristics
Excellent resource guide
on handwriting analysis.
Many factors can
influence the handwriting
of an individual, therefore,
knowing the background
of the individual providing
the handwriting sample is
very helpful.
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Handwriting Characteristics
• The position of the address on an envelope
also gives some clues to the writer’s
personality. You must first compare the
handwriting in the letter to that on the
envelope. They must have the same
general characteristics. If they look very
different, the writer is one who dissimulates
and lies and is generally not trustworthy.
*Country customs for addressing envelopes
must also be taken into consideration.
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Handwriting Characteristics
The absence of margins (the
whole paper is filled with writing)
is indicative of bad judgment;
selfishness; lavishness; intrusive
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personality; immaturity; neurosis
Handwriting Characteristics
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Handwriting Characteristics
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Handwriting Characteristics
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Handwriting Characteristics
The most positive
signature is one that
matches in every
aspect the
handwriting of the
address and the text.
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Handwriting Characteristics
On unlined paper use a ruler to establish baselines
and height.
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Handwriting Characteristics
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Handwriting Characteristics
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Handwriting Exemplars
• The collection of an adequate number of known
writings (exemplars) is most critical for
determining the outcome of a handwriting
comparison.
• Known writing should contain some of the words
and combination of letters present in the
questioned document and be adequate in
number to show the range of natural variations in
a suspect’s writing.
• The writing implement and paper should also be
alike.
• The writing of dictation and several pages may
serve to minimize attempts at deception.
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Exemplars
• An exemplar is an authentic sample used for comparison
purposes, such as handwriting.
• Exemplars are most critical for determining the outcome of a
comparison.
• Known writings of the suspect furnished to the examiner
should be as similar as possible to the questioned document
(writing implements and paper).
• If a person switches even from a pencil to a ballpoint pen
styles and habits may be altered. As well as if a paper is
ruled or un ruled, may also affect the handwriting of a
person who has become particularly accustomed to one
type or the other.
• Known writings should also contain some of the words and
combinations of letters present in the questioned document.
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Natural Variations
• Natural variations are normal
deviations found between repeated
specimens of an individual’s
handwriting or any printing device.
• Known writings must be adequate in
number to show the examiner the
range of natural variations in a
suspect’s writing characteristics.
• No two writings made by one
individual are ever identical in every
detail. This is even true for
signatures, no one ever signs two
signatures exactly alike.
• Variation is an inherent part of
natural writing.
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Authenticity
• Multiple sources are available to the
investigator for establishing the
authenticity of the writings of a suspect.
• An important consideration is the age of
the genuine document relative to the
questioned one.
• It is key to find standards that date
closely in time to the questioned one.
• In typical adults, basic writing changes
are very slow. Material written within 2-3
years of the disputed writing is valid for
comparison.
• As the age difference between the
genuine and unknown specimens
become greater, the standard tends to
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become less representative.
It may be difficult or impossible to obtain an adequate
set of collected standards.
In situations such as these, handwriting may have to
be obtained voluntarily or under court order from the
suspect.
The case of Gilbert v. California, the Supreme Court
upheld the taking of handwriting exemplars before
the appointment of counsel. They reasoned that
samples are identifying physical characteristics that
lie outside the protection privileges of the 5th
Amendment.
Also, in the case of U.S v. Mara, the court ruled that
taking a sample didn’t constitute an unreasonable
search and seizure of a person and hence didn’t
violate the 4th Amendment rights.
As you can see, there is ample case law to support 24the
constitutionality of taking handwriting specimens.
Requested writing samples may be consciously
altered by the writer, as opposed to non requested
specimens, which are written without the thought
that they may someday be used in a police
investigation.
Although, the investigator can take certain steps to
minimize attempts at deception.
The several page requirement normally provides
enough material that is free of attempts at
deliberate disguise or nervousness for a valid
comparison.
The writing of dictation yields exemplars that best
represent the suspect’s subconscious style and
characteristics.
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Steps to Minimize a
Conscious Writing Effort are:
• 1. The writer should be allowed
to write sitting comfortably
without distractions.
• 2. Under any circumstances,
the suspect shouldn’t be
shown the questioned
document.
• 3. The suspect should use a
pen and paper similar to the
documents.
• 4. The text should contain the
same contents of the
questioned document.
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Steps to Minimize a Conscious Writing
Effort are:
• 5. Dictation of the text should take place at least
3 times. Noticeable variations should appear
among 3 repetitions.
• 6. When the suspect is required to combine
other writings with a signature, signature
exemplars can be best obtained. The writer may
be asked to fill out about 20-30 checks or
receipts that will include signatures.
• 7. Last but not least, before requested
exemplars are taken from the suspect, a
document examiner should be consulted and
shown the questioned specimens.
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Other Document Problems
~Indented writings are impressions left on
papers positioned under a piece of paper
that has been written on.
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Indented Writing
~By applying an electrostatic charge to the
surface of a polymer film that has been
placed in contact with a questioned
document.
~Then impressions are revealed by applying
toner powder to the charged film.
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~ The work of the examiner goes beyond
visual examination.
~Chromatography is used for ink
comparisons.
~The use of thin layer chromatography can
be use to prove that a document has been
fraudulently backdated.
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Typewriter Issues
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Criminals use typewriters and
computer printers to write:
• Threatening letters
• Ransom notes
• Extortion notes
• Fraud
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When a typewriter is involved,
the document examiner
tries to:
 Determine the make & model of the
typewriter.
 Match up the note with a suspect
typewriter, if one is available.
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Typebar Typewriter
• A typebar typewriter is one in which the
typeface elements are permanently
fastened into the machine. Because each
machine has permanent, non-removable
typeface components, text can sometimes
be associated to the specific machine used
by comparing characteristics, such as
typeface damage or alignment defects, in
the text and machine.
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Typeface Typewriter
• The other type of typewriter has typeface
that is affixed to an interchangeable
element: a ball, printwheel, or (rarely)
thimble. The style of type is specific to the
individual element, not to the machine.
Therefore, although text may be
associated with a specific element, it can
rarely be associated with a particular
machine.
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Identifying the make and model
means that the examiner must
have access to a database of
typefaces used in various
typewriter models, new and old.
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Most manufactures use either pica or
elite typefaces, but the size, shape, and
style of the letters vary, making
identification possible.
Pica Typeface
Elite Typeface
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Ribbons
• Typewriters that use ribbons can help the
examiner link the typewriter to the
document.
• An examination of the type of impressions
left on the ribbon may reveal portion of the
ribbon on which a particular text was
typed.
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Case Study
Ted Kaczynski- A.K.A. “The Unabomber”
Forensic document examiners matched
the type written Manifesto to one of the
typewriters recovered from his cabin.
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2 Basic Typewriters
Typebar Typewriter
Typeface Typewriter
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Alterations, Erasures and
Obliterations
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Alterations, Erasures and
Obliterations
• Documents are often altered or changed after
their original preparation so the original intent
may be hidden and a forgery can be perpetrated.
• Document examiners must deal with evidence
that has been changed in several ways, such as
through alterations, erasures, and obliterations.
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Alterations
• Erasures by rubber erasers, sandpaper, razor blade or
knife to remove writing or typing disturb the fibers of the
paper and are readily apparent when examined with a
microscope.
• If an alteration is made to a document with ink differing
form the original, it can sometimes be detected due to
differences in the luminescence properties of the inks.
• Obliteration of writing by overwriting or crossing out to
hide the original writing can be revealed by infrared
radiation, which may pass through the upper layer of
writing while being absorbed by the underlying area.
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Examples of Questioned
Documents
• Letters, checks, drivers licenses, contracts, wills,
passports, suicide notes, currency and lottery
tickets are common questioned documents.
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Common Ways to Alter
Documents
• One of the most common ways to alter a
document is through erasure. Erasure is the
removal of writing, typewriting, or printing from a
document by using a chemical or one of the
following abrasive instruments:
• India rubber eraser
• Sandpaper
• Razor blade
• Knife
• All attempts at erasure disturb the upper fibers of the paper
and those changes are apparent when the suspected area
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is examined under a microscope using light.
Chemical Erasure
• Strong oxidizing agents are placed over
the ink which, under microscope
examination, reveal a discoloration on the
treated area of the paper.
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Obliteration
• The blotting out or smearing over of writing
or printing to make the original unreadable.
• Seldom used for fraudulent purposes because
its obviousness
• It it’s done with the same ink it is harder to
detect however, photography with infraredsensitive film may reveal the original writing
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Document Examination
Equipment
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Microscope
Infrared Techniques
Electronic Imaging
High and Low Intensity Ultraviolet
Photography
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Counterfeit Currency
• Counterfeiting of money is
one of the oldest crimes in
history
• During the Civil War, onethird to one-half of the
currency in circulation was
counterfeit
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Counterfeit Currency
• A national currency was
adopted in 1862 to resolve
the counterfeiting problem
• On July 5th, 1865 the United
States Secret Service was
established to suppress the
wide-spread counterfeiting of
US currency
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How to Detect Counterfeit
Money
• Portrait
• The genuine portrait appears lifelike and stands
out distinctly from the background
• Federal Reserve and Treasury Seals
• On a genuine bill, the saw-tooth points of the
Federal Reserve and Treasury seals are clear,
distinct, and sharp
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How to Detect Counterfeit
Money
• Border
• The fine lines in the border of a genuine bill are
clear and unbroken
• Serial Numbers
• Genuine serial numbers have a distinctive style
and are evenly spaced and they are printed in
the same ink color as the Treasury Seal
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How to Detect Counterfeit
Money
• Serial Numbers
• Genuine serial numbers have a distinctive style
and are evenly spaced and they are printed in
the same ink color as the Treasury Seal
• Paper
• Genuine currency paper has tiny red and blue
fibers embedded throughout
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If You Receive Counterfeit
Currency
• Do not return it to the passer
• Delay the passer if possible
• Observe the passers’ description, as well as that
of any companions, and the license numbers of
any vehicles used
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If You Receive Counterfeit
Currency
• Contact your local police department or the United
States Secret Service field office
• Write your initials and the date in the white border
areas of the suspect note
• Limit the handling of the note; carefully place it in a
protective covering, such as an envelope
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Typewriters & Printing Devices
• The two requests most often made of the
examiner in connection with the examination of
typewriters and printing devices are:
• Whether the make and model of the typewriter and
printing devices used to prepare the questioned
document can be identified
• Whether a particular suspect typewriter or printing
device can be identified as having prepared the
questioned document.
• In order to do this, the individual type character’s
style, shape, and size are compared to a
complete reference collection of past and
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present typefaces.
Characteristics From Use
• As is true for any mechanical device, use of a
printing device will result in wear and damage to
the machine’s moving parts.
• These changes will occur in a fashion that is both
random and irregular, thereby imparting individual
characteristics to the printing device.
• The document examiner has to deal with
problems involving business and personal
computers, which often produce typed copies that
have only subtle defects.
• Another area of investigation relates to the
typewriter ribbon, which may contain type
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impressions.
Digital Technology
• In the cases of photocopiers, fax machines, and
computer printers an examiner may be called on to
identify the make and model of a machine or to
compare a questioned document with test samples
from a suspect machine.
• A side-by-side comparison is made between the
questioned document and the printed exemplars to
compare markings produced by the machine.
• Examiners compare transitory defect marks, fax
machine headers, toner, toner application methods,
and mechanical and printing characteristics.
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Other Problems
• Infrared photography and reflecting light at different
angles are sometimes successfully used to reveal the
contents of a document that has been accidentally or
purposely charred in a fire.
• In certain situations, indented writings (partially visible
depressions underneath the visible writing) have proved
to be valuable evidence.
• It may be possible to determine what was written by the
impressions left on a paper pad.
• Applying an electrostatic charge to the surface of a
polymer film placed in contact with a questioned
document will visualize indented writings.
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Ink and Paper Comparisons
• A study of the chemical composition of the ink
used on documents may verify whether or not
known and questioned documents were
prepared by the same pen; and the paper itself
may be analyzed.
• A nondestructive approach to comparing ink
lines is accomplished with a visible-light
microspectrophotometer.
• Thin-layer chromatography is also suitable for
ink comparisons.
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VOICE
Examination
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Voice Examination
• The human voice may prove to be valuable
evidence for associating an individual with
a criminal act.
• The probability that any two individuals:
• Will have the same size vocal cavities
• (Throat, nasal, and two oral cavities formed by
positioning the tongue)
• Will coordinate their articulators
• (Lips, teeth, tongue, soft palate, and jaw muscles)
• In a like manner is so small as to make the
human voice a unique personal trait.
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Voice Examination
• Because we live in an era of telephone,
radio, and tape recorded communication,
the human voice now proves to be
valuable evidence for associating an
individual with a criminal act
• In order to do this, we use the sound
spectrograph, which is an instrument that
converts speech into a visual graphic
display.
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History of the Spectrograph
• The sound spectrograph •
was developed at Bell
Telephone laboratories in
1941. A Bell System
engineer named
Lawrence Kersta worked
with this device and
became convinced that
voiceprints could provide
a valuable means of
personal identification.
VOICEPRINT: A
pictorial
representation of the
frequency, duration
and amplitude of
human voice sounds
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The Sound Spectrograph
• The sound spectrograph is an instrument that
converts speech into a visual graphic display,
called a spectrogram or voiceprint.
• Courts have been asked to accept its results as
evidence of an individual’s participation in a
crime.
• At this time, however, there are still conflicting
opinions in the courts as to whether the
voiceprint has gained a sufficient degree of
general acceptance within the scientific
community to satisfy its admissibility as scientific
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evidence.
The Sound Spectrograph
• The spectrum portrays three parameters of
speech: time, frequency, and the relative
intensity or volume.
• When sufficient similarity exists between the
questioned and the known voice, a positive
conclusion is justified that both voices have
emanated from the same person.
• The recent introduction of the computerized
sound spectrograph simplifies the work today.
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The Sound Spectrograph
• Examiners apply both aural and visual
techniques when comparing two voice
samples.
• The examiner can than classify the recording
into one of seven categories ranging from a
positive identification, a probable
identification, a possible identification,
inconclusive, a possible elimination, a
probable elimination, or a positive elimination.
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The Sound Spectrograph
• Kersta believed that every voice has its
own unique quality and character, and that
there was small chance that any two
individuals have the same size vocal
cavities and coordinate their articulators
the same way, which would make the
voice a unique personal trait.
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The Pros and Cons
• Because of Kersta’s claim, many criminal
investigators have shown great interest in the sound
spectrograph. Many Law enforcement laboratories
have purchased them and many courts have to been
asked to accept the results of the sound
spectrograph as evidence of an individual’s
participation in a crime.
• However, there is some debate in the courts as to
whether or not the voiceprint has gained a sufficient
amount of general acceptance throughout the
scientific community for it to be considered
admissible as scientific evidence.
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The Pros and Cons
• The National Academy of Science feels
that the degree of accuracy and the error
rates of the voice identification varies from
case to case, therefore there is no
adequate scientific basis for legal
authorities to judge the reliability of the
voice spectrograph.
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How it works
• The two most important characteristics of
the voice are frequency and intensity.
Frequency is the speed at which air
particles vibrate. Intensity is the amount of
energy (loudness) in a sound wave or
pulse. No two sound waves will have
exactly the frequencies or intensities.
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How it works
• The expert who is using the sound
spectrograph must get sound samples from the
person in question. The sound samples are
played In a continuous loop throughout the
sound spectrograph. It will read the frequencies
and intensities and print out what looks very
similar to a recording of an earthquake tremor.
The expert will then compare the samples in
two ways: Aural (listening) and Visual. A
common way to perform aural analysis is to rerecord the selected segment. During the visual
comparison the spectrograms are placed side
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by side for rapid comparison
How it works
• The examiner can classify the recording into 7
categories as recommended by the American
Board of Recorded Evidence
• Positive Identification- 20+ similarities and all
differences accounted for
• Probable Identification- 15+ similarities and no
unexplained differences
• Possible Identification- 10+ similarities and no
unexplained differences
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How it works
• Inconclusive Decision- poor evidence
• A possible elimination- 10+ sounds with no
similarities
• Probable Elimination - 15+ sounds with no
similarities
• Positive Elimination- 20 + sounds with no
similarities
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