The Use of Fluorescent Powders in Police Work
| Published date | 01 March 1969 |
| Author | Grahame Devonport |
| DOI | 10.1177/0032258X6904200312 |
| Date | 01 March 1969 |
| Subject Matter | Article |
GRAHAME
DEVONPOkT,
B.Sc.
Home Office Forensic Science Laboratory, Harrogate
THE
USE OF FLUORESUENT
POWDERS
IN
POLIUE
WORK
The difficultyin investigatingcases involving the recurrent thefts of
articles (e.g., money) is well known to the police officer as is the
technique of marking these articles with a material, traces of which
can easily be identifiedwhen transferred to the hands and clothing of
the thief. Powders possessing a fluorescent colour when viewed in
ultra-violet light have been used for this purpose for some consider-
able time.
There is a fairly comprehensive selection of fluorescent powders
available, each powder having a distinctive colour in ultra-violet
light.
The principles which should govern the selection of a fluorescent
powder for thispurpose are as follows:
(a) The fluorescent colour of the powder must be vividly seen in
Ultra-violet light so as to leave no doubt in the mind of the
police officerand of the thief as to the source of the powder.
(b) The colour of the powder (in daylight) should blend with the
colour of the articles to be marked so as to be virtually in-
visible to the thief. To this end it may be necessary to mix the
powder with an inert material, e.g., starch or powdered graphite,
without seriously diluting the fluorescent quality ofthe powder.
(c) The fluorescent colour must be incapable of being confused
with other materials which may be encountered, e.g., pale blue
and white fluorescent colours should be avoided since it is
possible to confuse these with the various "whiteners" used in
washing powders.
(d) The powder should possess sufficient adhesive properties to
enable it to remain on the hands and clothing of the thief for
some time. Therefore the powder should have the consistency
of flour and not have a gritty feel when rubbed between the
fingers.
e) The powder, if necessary, must be capable of being quickly and
easily analysed in tiny amounts at the laboratory and therefore
mixtures involving several complex materials which may take
some time to identify should be avoided.
The powders now used by this laboratory are "Lumogen" (Regis-
tered Trade Mark) pigments which are used in the production of
surface coatings and printing inks. They fluoresce vividly in ultra-
violet light and conform to the five principles set out above. Other
March 1969 131
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