From The Herald (then “The Havana Herald”), 1971:
Havana Police Chief Bill Shelfer (C), Officer Charles Finch (L), and Officer Odis Carter all had a part in setting up the breathalyzer above, put into operation by the force in September, 1971. The chemical breath tester used to indicate alcohol content in the blood had been on hand for some time. Chief Shelfer pushed setting it up and Officer Finch, at that time, was the only qualified tester on the force. Officer Carter (cabinet maker) built the locked cabinet to house the machine. The law stated that if the results indicated more than .10 percent by weight of alcohol in the blood, “it shall be evidence the person is under the influence of alcoholic beverages.”