State v. Chavez
In State v. Chavez, 208 Ariz. 606, PP 3-4, 96 P.3d 1093, 1094 (App. 2004), a tribal ranger patrolling an Indian reservation observed the defendant "driving slowly, weaving, stopping, starting, and continuing to veer on and off the shoulder of the road."
Believing Chavez posed a danger to other motorists, the ranger activated his emergency lights and pulled Chavez over to the side of the road. Id. P 4. Chavez later was arrested for DUI. See id. PP 5, 8, n.2.
The Court held that the offense of driving under the influence of intoxicants (DUI) constitutes a misdemeanor amounting to a breach of the peace, and therefore a citizen's arrest for DUI can be lawful. 208 Ariz. 606, P 16, 96 P.3d at 1097.
The Chavez court agreed with the reasoning of the Fifth Circuit Court of Appeals that DUI constitutes a breach of the peace because it "threatens disaster and disorder and poses a potentially perilous public risk." Id. P 12.
The court also found that DUI is a breach of the peace because it endangers the driver's life, as well as the lives of other motorists. Id.
The Chavez court further found that the determination of whether a breach of the peace had occurred required a "case-by-case analysis of the facts and surrounding circumstances."
It did not hold that all citizen's arrests for traffic offenses are per se lawful or that traffic offenses are breaches of the peace justifying a citizen's arrest. Id. PP 12, 16.