A recent Nevada Supreme Court ruling shows there are limits on law enforcement officers conducting further investigation after a routine traffic stop.

In a case ruling Thursday, the court said “a traffic stop that is legitimate when initiated becomes illegitimate when the officer detains the car and driver beyond the time required to process the traffic offense” unless there are other circumstances to justify a prolonged stop.

The court suppressed as evidence cocaine found in the car of Kent Beckman, who was stopped for going 72 mph in a 65 mph speed limit zone on Interstate 80 in Elko at 7:30 a.m. Nov. 1, 2009.

After Nevada Highway Patrolman Richard Pickers verified Beckman’s driver’s license and registration, the officer issued a warning and told the driver he was free to leave eight minutes after the stop.

The court, in a unanimous decision written by Chief Justice Kristina Pickering, said the officer followed the law up to that point.

But the trooper became suspicious upon seeing fingerprints on the car’s trunk and said Beckman appeared nervous.

Pickers then proceeded to question Beckman further and told him he was not free to leave. Beckman refused to permit a search of his car.

A canine unit arrived and found cocaine in the car, and Beckman was arrested on drug charges at 7:40 a.m.

Elko District Judge Michael Memeo ruled the drugs were seized without a warrant and suppressed the evidence. The high court said that the trooper “unreasonably seized Beckman’s person in violation of the U.S. and Nevada Constitutions before the canine sniff and warrantless search occurred.”

The court said a prolonged traffic stop for further investigation is permitted if the driver gives his consent, the delay is “de minimis” (minor) and there is a justified suspicion of criminal activity. In this case, these exceptions were not present, it said.

“The government cannot benefit from evidence that officers obtained through a clear violation of an individual’s Fourth Amendment rights,” the court said.

The court noted there are two other cases pending that involve Trooper Pickers.