WASHINGTON - Aldo the drug-sniffing dog and his canine colleagues won a big treat at the Supreme Court on Tuesday, as justices unanimously approved a sniff search that had led to a Florida bust.

In a case closely watched by law enforcement officials and dog lovers alike, the court concluded that Aldo's alert signs during a routine traffic stop in Liberty County, Fla., had provided a sheriff's deputy with probable cause to conduct a search. The deputy didn't find the drugs Aldo was trained for, but did find materials used for making methamphetamine.

"Training records established Aldo's reliability in detecting drugs," Justice Elena Kagan wrote for all nine justices.

Although straightforward and relatively brief, the court's 11-page decision may have a broad reach for the many law enforcement agencies that rely on trained dogs. In accepting Aldo's training records as sufficient, the justices rejected a Florida Supreme Court ruling that would have required officials to produce a dog's field performance records - including instances of false alerts, when drugs weren't found - in order to demonstrate a dog's reliability when a search was challenged.

Kagan countered that the Florida Supreme Court's "strict evidentiary checklist" was too rigid in judging canine reliability, especially as "errors may abound" in a dog's field performance.

"The better measure of a dog's reliability thus comes away from the field, in controlled testing environments," Kagan wrote. "For that reason, evidence of a dog's satisfactory performance in a certification or training program can itself provide sufficient reason to trust his alert."

Underscoring the stakes, 24 states had sided with Florida law enforcement officials. The states - including Pennsylvania, Texas, Washington and Idaho - noted in a legal brief that "drug-detecting canines are one of the essential weapons in the states' arsenal to combat this illegal traffic."

Aldo, a German shepherd, had completed a 120-hour training course given by the Apopka, Fla., Police Department. He also had received a one-year certification from Drugbeat, a private Missouri-based company that trains and certifies dogs for law enforcement. Once certified, Aldo and his handler, K-9 Officer William Wheetley, underwent regular training sessions.