PORTLAND — The Maine Supreme Judicial Court has dismissed the state’s appeal of a lower court decision that may affect how solitary confinement is used in Maine prisons.

Diane Sleek, attorney for the Maine Department of Corrections, said Thursday that last week’s decision by Maine’s high court simply dismissed the appeal without giving definitive guidelines for the department — but that it does end the case.

That case began when inmate and convicted murderer Franklin Higgins challenged the right of prison officials to place him in solitary confinement based solely on an indictment. The Knox County Superior Court earlier had found that an indictment provided insufficient basis to place a prisoner in solitary confinement, and that a higher standard of evidence was needed. The department of corrections appealed that decision to the Maine Supreme Judicial Court.

“Mr. Higgins, when he filed his lawsuit, he was complaining about the fact that he was in segregation in the prison. By the time this wound its way up through the courts, he’d been released from segregation,” Sleek said. “So the law court decided the matter was moot.”

Higgins, who is serving a 45-year prison term, spent two years in solitary confinement at Maine State Prison after he had been indicted for murder in 2011 by the Knox County Grand Jury in connection with the beating death of fellow prisoner Lloyd Millett.

That charge later was dropped and Higgins was indicted in April 2012 on a different charge, aggravated attempted murder, in connection with Millett’s death. A Knox County jury acquitted him on that charge the following March, after the defense successfully argued that the murder was in self-defense.

However, Higgins was held in administrative segregation, or solitary confinement, for two years while the case was progressing. Kevin Decker, his student attorney from the University of Maine School of Law, argued earlier this month before the Maine Supreme Judicial Court that by basing its decision to segregate Higgins on the murder indictment, the Maine Department of Corrections outsourced its authority to the grand jury. Because grand jury proceedings are secret, Decker said, a prisoner cannot challenge its findings.

“We did get what we wanted,” Decker said after the high court ruled.

He said he worked on Higgins’ case through the Cumberland Legal Aid Clinic at the law school.

In her arguments, Sleek told the supreme court justices that the lower court’s decision would restrict when the department could place a prisoner in segregation and might interfere with ongoing police investigations or the safety of other prisoners.

Sleek said this week that because the case was ruled at the superior court level and because the law court did not rule on the underlying issue, it does not technically set a legal precedent.

As for whether the decision will change how the department of corrections decides to place prisoners in segregation, Sleek said she was not “really prepared to talk about that.”

But Jim Bergin of the Maine Prisoner Advocacy Coalition said Friday that he doubted whether the Knox County Superior Court’s decision will have a significant impact on the department’s ability to use solitary confinement.

“I don’t think it has too much significance, to tell you the truth,” he said Friday. “Either for your protection or for other people’s protection, if they want to get you in segregation, they will. The prison has a policy. If somebody does something to require someone to be locked down for a couple of days, they’re going to do it.”

Higgins was sentenced in 2001 to serve 45 years for the Feb. 27, 1999, murder of 40-year-old Katherine Poor of Kenduskeag.

BDN Writer Stephen Betts contributed to this report.