Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-08-11
u. S. STARTS DRIVE TO CURB
POISON-PEN LETTER WRITERS
Manual on Identifying Type.
writer's and Guns Is
Being Prepared.
Studies of System Explained
by Souder, Standards
Bureau Expert.
BY WILL p. KENNEDY.

Uncle Sam has started a relentless
campaign to apprehend the writer's Of
poison-pen, and blackraail letters and
! by the same system to trail down too
promiscuous users OF shooting irons TO
settle arguments.
| Specialists are now writing a book
which will be manual for officers Of
the law and other sleuths in identifying
| typewriters and guns by precision
| methods Of comparison and measure
ment. This book will not be available
until next year. It will be issued by
the Bureau of Standards, which was
one Of the pet units of the Department
Of Commerce. under the administration
Of Herbert Hoover.
Wilmer Souder, an expert In the
Bureau Of Standards, explains the
studies that have been made for iden-
tif1cation by comparison, bringing up
to date. system which has been more
or less successful for centuries. The
application of precision measurement
methods Is Of recent origin, and is not
generally understood, he points out.
This lack OF understanding of the prir-
cfpleS upon which this science Is based
is responsible for the confusion so often
resulting from evidence introduced in
courts Of law, he said.
Accustomed 10 Usual Methods.
I'VE are so accustomed to the usual
methods of description, which are only
approximate. and by virtue Ct snese
approximations are susceptible of no
precise Interpretation" he explains,
that we fail to recognize the extreme
accuracy Of identincattons made by
precision measurements.
When We say we are looking for
man 6 feet tall of rather heavy build.
with dark hair, with a scar on one
hand, and with some gold teeth in his
mouth, we should not be surprised to
ind several hundred citizens of the
United States who meet the descrip-
ton. If we increase the precision OF
the description to q man 1914 inches
tall. weighing 207 pounds, index finger
OF the left hand amputated at the sec
ond joint. and with gold crowns on left
cuspid and right bicuspids. we may feel
sure there Is not more than one man
In the entire country who will meet the
specifications Having found this one.
further search cannot be justified with
out the introduction of some unusual
condition.
THE Justification of this definite
conclusion of positive Identification is
based on the law of probability Briefly
and in non-technica1 terms, this law is
interpreted from the fraction which
represents the ratio of the number of
times specific characteristic appears
divided by the maximum number Of ap-
pearanceS possible, and for two or more
characteristics appearing simultane-
sented by the product Of the individual
fractions"
Seeks to Establish Standards.
The U. s. Bureau of Standards has
taken UP the problems of indentiflca-
ton Of typewriter documents, guns,
bullets, ETC., in an effort to establish
standards of this class of work. The
bureaus interest Is purely scientific and
1t Is not prepared to handle cases in
court. Its work, however, is expected to
lead State. county and local authorities
to a more exact procedure in court
cases, and is expected to have an i'm
portant effect on the practice of law.
There are now available q few ex-
perts to make identiflcations In logi-
cal and precise manner, but there are
many so-called experts who recognize
no limitations, no standards and no
equipment as essential in this field.
The instruments which are now gen.
orally recognized for satisfactory work
in these fields are the result of years
Of effort on the part Of men who have
been actively engaged in this work, and
who have recognized the value of in
creased precision in making COMPARE
sons Of data available for identifications.
In each instance the positiveness Of
identification increases with the In
crease in number of agreeing character
istics, the narrower limits of measure
ment and the increase In precision of
measurements. When, If ever, these
ideal conditions are established there
will be fewer conflicting expert opinions.
Different Type Styles.
Precision measurements are the pri-
mary standards for identification of
questioned documents, Mr.. Souder en-
phasizes. The typewriter page may at
first glance appear to be perfect piece
Of work, and not susceptible to an
analysis Of numerous individual char
acteristics which will prove 1t to be be-
yond question Of doubt the product of
one and only one certain machine.
Type styles and characteristics distin-
guish one make Of machine from an
styles Of type usually differ In dimen-
sional proportions Of the individual
letters. For example, the "i'' is given the
same space as the "w" In typewriter
document, and it Is the problem of the
artist to design these and other letters
as to minimize what would easily ap-
pear to be excessive crowding or isola-
ton Of type In the printed work. The
modification Of letters to avoid these
effects gives the first opportunity for
precision measurements.
For type made from the same model,
or formed against the same dye, we
may look for defects or lack of all de-
tails of perfection over the lines OF the
letter face, Mr.. Souder points out
The process of plating and polishing
may add defects. The more sure
source for identification, however, lies
in the adjustment Of the type on the
hars. after the machine has been COM
.pletely assembled. Some letters will