Evening star., 1951-05-21
Science of Detection
Seems Almost Magic
FBI Laboratory and Files
Aid Fight Against Crime
By Thomos R. Henry

Aid Fight Against Crime
By Thomas R. Henry
The detective has gone super-micro-
scopic.
He tracks criminals by grains of dust
on cobwebs. by faint traces Of paint on
clothing
Growing from single man with a
microscope in 1888, the Federal Bureau
of Investigation now maintains in
Washington scientific laboratory with
equipment and files whose findings must
seem magical to law-breakers. This
laboratory was described to the Wash
ington Academy of Sciences the other
night by it's chief. DR.. D. j. Parsons.
Handwriting tests, ballistics tests and
f1ngerprints. while still useful, now are
elementary stuff to the real scientific
detective.
A notable part of the laboratory are
its extensive flles-paint files, auto tire
and heel files bad-check files, fuse files,
ammunition files and half dozen others.
These. of course, are growing every
day as new data is obtained from the
field.
A notable example described by DR..
Parsons is the "bad check" files. Pass
ers of fraudulent checks constitute
special and not particularly vicious
type of criminal. They often are quite
successful, sometimes making small for
tunes in few years. They usually
stay in the business most Of the time
they manage to stay out of Jail. But
each man operates more or less accord
ing to a pattern. Once he is convicted
specimens of his checks go into the
file. Thenceforth, whenever a bad
check is received it is fairly easy by
a quick reference to the file to deter
mine whether this particular man is
the perpetrator. It often is possible
to follow him from city to city. In
some cases it is possible to establish
a route which he almost invariably
follows and to trap him in the next
city he visits.
Automobile Parts Analyzed.
Formerly investigation of a hit-and-
run fatality was extremely laborious.
Today the FBI laboratory keeps up to
date file of all the paints used on
American automobiles so that II the
slightest trace of this is found on the
clothing Of the victim the type of car
can be determined Immediately. OF
course, 1t may have been repainted.
This is all to the good, so far as the
FBI Is concerned. The base paint is
still the same and the extra coat IS
a means of pinning the offense more
easily to the driver of one particular
car. DR.. Parsons told Of one instance
where car had been repainted II times.
This showed in the paint left on the
victims clothing. 1t makes identifl-
cation Of suspect absolutely certain.
It is seldom any more that an elabor-
ate and laboriouS chemical analysis Of
the paint is necessary, at least >ntil the
case reaches an advanced stage. A
flash of one of the bureaus specialized
Spectroscopes usually is enough to de-
termine whether clue is worth purSu-
ing.
There is very extensive hair file,
both for humans and animals. 1t Is
seldom that person can positively be
identified by few hairs or, for that
matter, by samples of blood. But it can
be determined that suspect was not
involved. In one recent bank robbery
case the hair test worked the other way.
The bandit dropped his cap in the bank.
He was described as a man with con-
spicuously red hair. Red hairs were
found in the cap. But, examination
showed he had. not always been red
headed. Eleven layers of dye were found
The man, it later developed, had his
hair dyed not only for each new job
but for the various preliminary opera
tions such as casing bank. This
pinned the crime down to one suspect.
Exposing Draft Hoaxes.
During the war hundreds took heavy
doses of benzedrine sulphate before ap-
pearing before an induction board. The
effects Of the drug simulated serious
heart condition. It was possible to
detect such a draft dodger, but only
by an involved chemical process which
required three or four days. If all
suspects had been investigated the FBI
would have had time for very little
less. Now. with the use Of a giant
spectroscope, it is possible to get the
same information in little more>than
minute.
Other tests have been devised for
loaded dice. These come into the FBI
field when used by gamblers on inter-
state trains or boats in coastal waters.
One of the finest bits Of laboratory
detection came by making use of the
dust on cobweb A window had been
forced in burglary case. A cobweb
had been broken and bit Of cobweb
found on the clothing Of one suspect.
It soon appeared that it would be i'm
possibly laborious to attempt to match
this tiny strand with any part Of the
broken cobweb in the window. The dust
on both, however, was found to be iden-
tical and thus the case against the sus-
pect was strengthened.
Questions and Answers