I. Includes the physical
and chemical analysis of writing
materials
A. Techniques used
1. Chemical and physical analysis,
and photography
B. Types of Analysis
1. Paper
a. Can be prepared with a variety
of raw materials
- textures can be different
b. Different papers exhibit different
properties
-different colors
-different weights
-some fluoresce under ultra-violet
light
c. Watermark
-translucent mark placed on paper
by the manufacturer
- can establish approximate age of
document and possible location of
store
2. Ink
a. Colored liquids composed of a
number of substances in a solvent
b. Not easy to trace a pen, but
easy to identify the ink
c. Chromatography is used
d. Age of the ink can sometimes
be determined
3. Pencils
a. “lead” in pencils is a mixture of
graphite, clay and kaolin
b. More graphite = softer pencil,
more clay=harder pencil
c. Examination of marks can
determine pencil “softness” and
order of marks made
4. Typewriter
a. Type is compared to the FBI
Typewriter Standard Files
b. Make and model of machine
can be determined
II. Document forgeries
A. Involves
1. Forging a signature
2. Erasing a statement and
replacing it with another
3. Adding words to what is
already there
B. Determining authorship
1. Handwriting is the product
of 2 things
a. physical movement of the
hand
b. subconscious activity of
the mind directing the hand
2. Forgery by tracing – there will be
a lack of smoothness to the lines
3. Also need to note techniques, for
example:
-size of letters in relation to each
other
-spacing
-slant and curves of the letters
C. Erasures - Two types
2. Mechanical erasures
a. accomplished by rubbing the
ink or pencil mark with an
abrasive substance
b. can be indicated by iodine
fuming but the words will not
show
3. Chemical erasures
a. accomplished by chemicals that
bond with the ink and make them
colorless
b. still visible under ultraviolet
light
D. Invisible inks (secret message)
1. Use organic liquids (milk, lemon
juice) and heat paper gently
2. Chemical solutions that are
colorless until treated with a
second chemical
3. Chemicals that are colorless
under normal light but show up
under ultraviolet light