Data were gathered from the police report forms concerning the method of detection of the drunk driver (alcohol check, routine check, driving behavior, or accident). These four groups were compared with a number of selected variables, such as age, recidivism, blood alcohol concentration (BAC), refusal to submit to a blood test, use of drugs in combination with alcohol, Michigan Alcoholism Screening Test (MAST) score, and work situation. In spite of the extension of police authority, it was found that 64.5 percent of DWI (driving while intoxicated) drivers were still apprehended on classic grounds of driving behavior or accident. Comparison of variables showed significant differences for age and BAC. The study found sufficient evidence to conclude that the increased police authority has resulted in the apprehension of more social drinkers than problem drinkers, but 63 percent of the sample had a BAC of 1 percent or more, while the legal limit is 0.5 percent. Since many experts consider detection in an early state of drinking 0.5 percent. Since many experts consider detection in an early stage of drinking to be important, it would appear that increased police power to apprehend drunk drivers in an easier way was justified. Ten footnotes and seven tables are included.