In ruling unanimously for five officers attached to the Central Utah Narcotics Task Force, the court also abandoned a rigid, two-step test that it adopted in 2001 to guide judges in assessing alleged violations of constitutional rights.

Trial and appellate judges "should be permitted to exercise their sound discretion" in evaluating such claims, Justice Samuel Alito said in his opinion for the court.

Under the 2001 ruling, courts first had to determine whether an action amounts to a violation of a constitutional right and then decide whether the public official, often a police officer, should be immune from the civil lawsuit.

Officials can't be held liable in situations where it is not clearly established that their actions violated someone's constitutional rights.

The case grew out of a search of the home of Afton Callahan of Millard County, Utah, in 2002.

An informant contacted police to tell them he had arranged to purchase drugs from Callahan at Callahan's trailer home.