WASHINGTON — The U.S. Supreme Court overturned Utah courts in a ruling handed down Monday that found Brigham City police officers did nothing wrong six years ago when they entered a house without a warrant to break up a fight.

The Utah Supreme Court, Court of Appeals and the trial judge ruled that the police had violated the Fourth Amendment rights against unreasonable searches of the people arrested.

But the top court unanimously sided with state prosecutors, saying the officers' entry without a warrant and without knocking was "plainly reasonable under the circumstances."

Brigham City Attorney Stephen R. Hadfield said his office will pursue the misdemeanor case that has been on hold for several years during the appeals.

And police Lt. Michael C. Nelson said the ruling came as a relief.

"It will have the effect of easing the oftentimes heavy burden placed on upon our police officers when responding to disturbances in residential neighborhoods," he said.

On July 23, 2000, Brigham City police officers saw a fight going on inside a home between four adults and a teenager. The teenager broke free and punched one of the adults in the face. The officers yelled "Police" but it was so loud inside no one heard them. They went inside to stop the fight and made arrests.

A Utah district court judge originally threw out the charges because the police had no warrant to enter the home and he ruled they were not justified in being there — a decision the Utah Court of Appeals and the Utah Supreme Court each affirmed. The Utah Attorney General's Office appealed, and the case was heard in April.

In a 9-0 decision, Chief Justice John Roberts wrote that the "melee" the officers witnessed gave them an "objectively reasonable basis for believing both that the injured adult might need help and that the violence in the kitchen was just beginning."

"Nothing in the Fourth Amendment required them to wait until another blow rendered someone 'unconscious' or 'semi-unconscious' or worse before entering," Roberts wrote. "The role of a peace officer includes preventing violence and restoring order, not simply rendering first aid to causalities; an officer is not like a boxing (or hockey) referee, poised to stop a bout only if it becomes too one-sided."

Roberts said one of the police officers announcing his presence by yelling "Police!" was "at least equivalent to a knock on the screen door." He said there was no violation of the Fourth Amendment's knock-and-announce rule.

Utah Assistant Attorney General Jeffrey Gray, who argued the case before the U.S. Supreme Court, said the ruling "reaffirms that the Fourth Amendment does not keep officers from doing what we expect officers to do — protect the public from harm."