My book about the history of Public Safety Dispatching is done and I'm in process of looking for a publisher.
Here is an excerpt from the dispatcher book:
On April 7th, 1921, Detroit Police Commissioner William Rutledge endorsed a little technological experimentation within the ranks of his department. He authorized one-way radio service with radios installed in the police vehicles. Commissioner Rutledge hired his nephew, Bernard ‘Barney’ Fitzgerald, to be the Department’s first dispatcher. The transmitter was housed in the 9th Precinct, on the second floor in December 1922. Detroit Police Department dispatch was closed on Sundays; twenty-four hour service started in 1929. The radios worked, but as with many of the early broadcast & receive only mobile units, the system was inconsistent. To make certain the equipment functioned, the time and call sign was given every fifteen minutes. After each incident was complete, police officers had to call in to dispatch to clear the calls (they ‘phoned home’ long before ET made his theatrical debut).
Chicago Police came on board with radios in 1929. The initial radio traffic was done via a broadcast station status, not as a public safety licensee. Field units could get a jump on a crime within a reasonable amount of time with dispatchers putting out information over the airwaves. Convinced the electronic gadget was worth the expense, the agency installed a radio system on the 9th of August,1930, in the main Police Headquarters where the primary switchboard was maintained.
Stay safe out there!