The lawsuit comes as lethal injections have drawn greater scrutiny, from whether the drugs are effective to whether the execution personnel are properly trained.
It's unclear how the ruling will affect the scheduled execution next week of Idaho death row inmate Richard Leavitt, who will be put to death by lethal injection. Leavitt was convicted of the 1984 murder of a Blackfoot woman.
"We, of course, respect the court's decision. We will take the necessary measures to assure that the execution continues as scheduled," said Idaho Department of Correction spokesman Jeff Ray.
A federal judge Tuesday denied a request from the news groups seeking to prevent Leavitt's execution without the changes. The news organizations appealed that ruling to the 9th Circuit.
The appellate judges, during arguments Thursday, noted that the 9th Circuit had already ruled in a 2002 California case that every aspect of an execution should be open to witnesses, from the moment the condemned enters the death chamber to the final heartbeat.
The decade-old decision established what was expected of the nine Western states within the court's jurisdiction. A decade later, four of the states have kept part of each execution away from public view, according to death penalty experts.
"Nearly a decade ago, we held in the clearest possible terms that 'the public enjoys a First Amendment right to view executions from the moment the condemned is escorted into the execution chamber," the judges said in their ruling Friday. "The State of Idaho has had ample opportunity for the past decade to adopt an execution procedure that reflects this settled law."
Idaho, Arizona, Washington and Montana have conducted 14 lethal injections since the 9th Circuit ruling in 2002, and half of each procedure has been behind closed doors.
Chuck Brown, an attorney for the news organizations, predicted that the 9th Circuit ruling over Idaho's execution process will prompt those remaining states to change their policies to allow for a full viewing of the execution process.
"That's exactly what will happen," said Brown, who added that the ruling clears up any uncertainty about the intent of the 9th Circuit's 2002 decision. "It clears up any doubt."
While U.S. District Judge Edward J. Lodge took issue with the timing of the May 24 request from the news groups, saying it was too close to Leavitt's execution, the 9th Circuit disagreed, saying the state was at fault. The appellate judges noted that media representatives had asked prison officials to alter the execution procedure before November 2011 execution of Paul Rhoades.
The news organizations filed their case after talks were unsuccessful with prison officials, who took the position that the 2002 ruling was based on facts unique to California, Brown said, citing letters from Idaho correction director Brent Reinke.
"We fault the State, not the media plaintiffs, for our need to consider this question several days before an execution: the State has missed opportunity after opportunity to bring its execution procedures into compliance with the clear law of this Circuit," the ruling also said.
During arguments on Thursday, Judge Marsha Berzon questioned why Idaho should be an exception when other states have decided that entire executions can be seen by the public.
"California has been doing it. Ohio has been doing it. Arizona just announced they are going to do it," Berzon said. "You haven't put anything in the record that Idaho is different in this regard. That you haven't done."