SANDPOINT - The Idaho Court of Appeals is rejecting yet another effort by a Sandpoint man to have his life sentence reduced for his role in the killing a U.S. Forest Service law officer in 1989.

Joseph Earl Pratt is serving the sentence for his involvement in the murder of Brent "Jake" Jacobson, who tracked Pratt and his brother, James, to the Smith Creek drainage following a failed home-invasion robbery in Sagle.

Jacobson and Bonner County Sheriff's Deputy Steven Barbieri trudged through waist-deep snow in the rugged drainage and found the brothers sleeping under a tree after a lengthy search. James Pratt opened fire with a 12-gauge shotgun, which left Jacobson mortally wounded.

The Pratts later surrendered to police and were ultimately convicted of first-degree murder, kidnapping, robbery and other charges.

James Pratt was sentenced to death by lethal injection, but the Idaho Supreme Court later converted the sentence to life without parole. Joseph Pratt was also sentenced to life.

Joseph Pratt appealed his conviction and in 1994 the supreme court held that Jacobson was not acting in lawful discharge of an official duty because his authority did not extend outside of the national forest system. However, the high court affirmed the conviction because there were alternative first-degree predicates, namely robbery and kidnapping.

Joseph Pratt has since filed repeated motions in 1st District Court for a reduction in sentence on grounds the life term was illegally imposed. Those motions were denied, rulings which were later upheld by the appeals court.

In his eighth and latest effort filed last year, Joseph Pratt argued that the district court impermissibly considered the fact that Jacobson was acting in the line of duty because Jacobson was outside his jurisdiction.

First District Judge Barbara Buchanan denied the motion. Buchanan ruled that the motion was barred by a legal doctrine which bars the re-litigation of claims that have already been finally decided.

The appeals court affirmed Buchanan's ruling, according to an unpublished opinion released on Tuesday.

"The fact remains that Pratt and his brother were convicted of engaging in a series of criminal acts, including a shoot-out with officers, which led to the death of a peace officer," Chief Judge Sergio Gutierrez and judges Karen Lansing and John Melanson said in the four-page opinion.

Joseph Pratt, 53, is serving his sentence at the Idaho State Correctional Institution in Kuna, according to the Idaho Department of Correction. James Pratt, 55, is serving his term at the Kit Carson Correctional Center in Burlington, Colo.

Jacobson was posthumously awarded Idaho's Medal of Honor in 2011.