Furthermore, probable cause is an objective test. The relevant inquiry is whether the facts would lead a reasonable police officer to believe that a violation had occurred or was occurring. Weiss, or any other reasonable police officer, could have disbelieved Wehe regarding the significance of his physical conditions. The Swanson court determined these three indicia formed a basis for a reasonable suspicion, but were not enough for probable cause. The facts before us differ markedly from the facts in Swanson .
Probable cause is a test with a very low threshold.
The evidence need not even reach the level that guilt is more likely than not. Wehe also argues that the City of Wautoma should not be allowed to use field sobriety tests to determine probable cause because the city failed to show how sobriety tests are probative of intoxication. Wehe claims the city must prove that sobriety tests are reliable indicators of intoxication before they can be used to determine intoxication. Since Wisconsin's appellate courts have not directly addressed this issue, we examine authority from other states. The Illinois court stated that intoxication can be understood by lay persons, and therefore expert testimony is not needed.