Evening star., 1929-07-01
CHICAGO WILL ASK
WAVE FOR POLICE
City to Request Radio Chan
mel to Aid Crime
Suppression.
BY MARTIN coDEL.

When photo-radio picture was
flashed across the ocean to the police
on the other side to identify and appre-
hend a criminal known to be fleeing
aboard steamer outbound from New
York a graphic demonstration was
given of the part radio can play in
police work
Photo-radio has an important role,
carrying images and fingerprints be-
tween cities and between countries. But
the American police forces are finding
the radio, telephone and telegraph still
more useful in their everyday fight
against crime.
Chicago's police department for ex-
ample, is about to come to the Federal
Radio Commission for a frequency
whose carrier wave shall be broadcast
at all hours of the day-ready, instan-
taneously, to carry orders to policemen
in the field On this wave orders would
be transmitted to squad cars in the va
rious precincts, so that they may be
dispatched Immediately to the scene OF a
crime.
Cars Now Equipped.
The squad cars in Chicago are already
equipped with radio receivers. They
are now to be tuned to the wave
lengths of station WGN, which inter-
rupts its programs at any time to an
nounce instructions to certain cars to
hurry to designated points. But there
are several disadvantages. One is that
the calls are heard by the public. And
large crowds invariably gather at the
addresses mentioned. Another is that
the criminal himself is likely to hear
the alarm and escape before the police
arrive. In one instance burglar heard
the call while rifling home. He made
his getway at once after leaving a note
on the loud speaker chiding the police
Hence Chicago, like other big cities,
wants to use a wave length to which
the ordinary radio receiver cannot be
tuned. The Federal Radio Commission
has already set aside one such channel
for joint use by all police departments
It is on the continental short-wave band
at lilo kilocycles CTS meters). The
police departments of. New York, De-
troit, Cleveland and Cincinnati already
are using it.
Detroit Uses System.
Detroit's system is highly efficient.
The Detroit police department has a
feet of automobiles cruising the streets,
all radio equipped and all tuned to the
frequency of the police transmitter
Test calls are transmitted at regular
intervals. Something like 10000 alarms
were sent out in one year, and they
were responGible for many arrests. Once
the Detroit police were able to surround
a building where a burglary was re-
ported and catch the burglar in the act.
Shooting through the ether at a
speed of 10000 miles second, radio
Is obviously the fastest means of COM
munication known to man. Thus it is
natural that police should find it
handler than the wire telephone, tele-
graph or alarm method of.-informing
men on the beat of crimes reported to
central headquarters from their vicin-
ity. Several tiny radio receiving sets
have been invented to be carried by
policemen while patrolling their beats,
but general use of these has not been
made as vet.
internationally the value of radio in
criminal pursuit is recognized by the
proposal made at the recent Prague
conference that two wave lengths be set
aside for international police USE This
is likely to be adopted at the technical
consulting conference to be held at The
) Hague next September
{Copyright, 1929. by North American News
paper Alliance.)