BOISE, Idaho — The Idaho Supreme Court has rejected an appeal from a Blaine County woman who was convicted of killing her parents while still a teen in 2003.

Sarah Marie Johnson was sentenced to life without parole in 2005 for fatally shooting her father, 46-year-old Alan Johnson, and mother, 52-year-old Diane Johnson. At the time, prosecutors said Johnson killed her parents after fighting with them over her relationship with an older man.

In a ruling handed down Friday, the Idaho Supreme Court said Johnson’s two fixed life sentences don’t violate the U.S. Constitution’s Eighth Amendment, which bars cruel and unusual punishment.

The unanimous court agreed that two recent U.S. Supreme Court rulings forbid mandatory life sentences for juveniles. But they said those rulings didn’t impact Johnson’s case because the sentencing judge considered her age as a mitigating factor before sentencing her to life in prison.

That’s because the U.S. Supreme Court rulings left it up to states to decide how to enforce the constitutional restrictions on juvenile sentences, essentially requiring that a judge consider the juvenile offender’s youth and attendant characteristics before determining that life without parole is appropriate, the Idaho Supreme Court found.

The trial court in Johnson’s case held a hearing to determine whether the crime was one that “reflected the transient immaturity of youth,” Idaho Supreme Court Chief Justice Roger Burdick wrote in Friday’s ruling. That hearing was the sentencing hearing, Burdick wrote, during which experts testified about the developmental state of an adolescent’s brain, among other things. The trial judge also made specific references to Johnson’s youth during the sentencing, showing that it was weighed against the heinous nature of her crimes, the high court found.

That’s enough to satisfy the requirements of the U.S. Supreme Court rulings, Burdick wrote.

“We recognize the holdings in Miller and Montgomery apply to Idaho, but affirm the district court’s ruling that the substantive requirement in those cases — that the sentencing court holds a hearing that considers the youth of the offender — was met,” Burdick wrote.

The Idaho Supreme Court also found that Johnson isn’t entitled to have new testing run on DNA samples collected after the murders, and that claims that her attorney was ineffective during an earlier post-conviction appeal aren’t a sufficient reason to justify a second post-conviction appeal.