[1] In December 1992, Detective Pautz of the Milwaukee Sheriff's Department was conducting drug interdiction when he noticed a 1981 two door Oldsmobile with California plates.

[2] Pautz radioed his dispatcher to check the registration of the car, and he ran the name of the owner, Miguel Ledesma Ornelas, through the Narcotics and Dangerous Drugs Information System (NADDIS).

Justice Scalia dissented, arguing that probable cause determinations are necessarily fact intensive and unsuited to de novo review by an appellate court.

[9] Ornelas was initially viewed as a victory for criminal defendants because de novo review was thought to be more critical and searching than deference to the District Court.

[10] David Sklansky, however, suggests that the "due weight" given police inferences is actually more favorable to law enforcement than a clear error standard for reviewing District Court determinations.