State v. Robert E. Post, 2007 WI 60, reversing unpublished decision
For Post: T. Christopher Kelly
Issue/Holding1: Weaving within lane of travel doesn’t support bright-line rule justifying stop for suspicion of drunk driving:
¶14 The State contends that Sergeant Sherman had reasonable suspicion to stop Post. It advocates the view that repeated weaving of a motor vehicle within a single lane (absent an obvious innocent explanation) provides the reasonable suspicion to make an investigatory stop. While we agree that the facts of the case give rise to a reasonable suspicion that Post was driving while intoxicated and that the investigative stop was reasonable, we reject the bright-line rule that repeated weaving within a single lane alone gives rise to reasonable suspicion. Rather, our determination is based on the totality of the circumstances, in accord with Wisconsin jurisprudence.
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¶19 Further, the State’s proffered bright-line rule is problematic because movements that may be characterized as “repeated weaving within a single lane” may, under the totality of the circumstances, fail to give rise to reasonable suspicion. This may be the case, for example, where the “weaving” is minimal or happens very few times over a great distance. [4] Courts in a number of other jurisdictions have concluded that weaving within a single lane can be insignificant enough that it does not give rise to reasonable suspicion.[5] In such cases, weaving within a single lane would not alone warrant a reasonable police officer to suspect that the individual has committed, was committing, or is about to commit a crime.
¶20 In addition, the rule that weaving within a single lane may alone give rise to reasonable suspicion fails to strike the appropriate balance between the State’s interest in detecting, preventing, and investigating crime with the individual’s interest in being free from unreasonable intrusions. …
¶21 Because the standard proffered by the State can be interpreted to cover conduct that many innocent drivers commit, it may subject a substantial portion of the public to invasions of their privacy. It is in effect no standard at all. Adopting it here would allow essentially unfettered discretion and permit the arbitrary invasions of privacy by government officials addressed by the Fourth Amendment and Article I, Section 11. …
The court, footnote 6, rejects comparison of discretionary cause-based and discretionless check-point stops such as authorized by Michigan Dept. of State Police v. Sitz, 496 U.S. 444, 451-55 (1990): the very basis for the latter is their “minimally intrusive nature,” such that reliance to bolster a discretionary stop would “turn that [principle] on its head.” Nor is there a bright-line rule that would permit a stop only where movement is erratic, unsafe, or illegal supportable:
¶22 Like the State, Post offers a bright-line rule for determining reasonable suspicion. He argues that movements within a lane can give rise to the reasonable suspicion necessary to justify an investigative stop only where the movements are erratic, unsafe, or illegal. [7] We reject this bright-line rule as well.
¶23 Post’s claim that lateral movements must be erratic, unsafe, or illegal in order to generate reasonable suspicion is belied by our decision in Waldner. …
¶24 Further, it is clear that driving need not be illegal in order to give rise to reasonable suspicion. … We therefore determine that a driver’s actions need not be erratic, unsafe, or illegal to give rise to reasonable suspicion.
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¶26 Thus, we adopt neither the bright-line rule proffered by the State that weaving within a single lane may alone give rise to reasonable suspicion, nor the bright-line rule advocated by Post that weaving within a single lane must be erratic, unsafe, or illegal to give rise to reasonable suspicion. Rather, we maintain the well-established principle that reviewing courts must determine whether there was reasonable suspicion for an investigative stop based on the totality of the circumstances.
