The U.S. Supreme Court will hear an appeal Wednesday by an Arizona death row inmate who is seeking a new sentencing trial, arguing the horrific physical abuse that he suffered as a child wasn't fully considered when he was first sentenced.

The appeal of James Erin McKinney could affect as many as 15 of Arizona's 104 death row inmates. Attorneys say the Arizona courts used an unconstitutional test in examining the mitigating factors considered during the sentencing trials of the inmates.

The Supreme Court has ruled both that juries, not judges, must impose death sentences, and that mitigating factors, including childhood deprivations, must be factored into sentencing decisions.

McKinney's attorneys say the Arizona Supreme Court erred last year in upholding his sentences after a federal appellate decision concluded that the state court used an unconstitutional test in examining the mitigating factors considered during his sentencing.

Prosecutors said McKinney shouldn't get a sentencing retrial, arguing his case was considered officially closed years before the 2002 Supreme Court decision that required death penalty decisions to be made by jurors, not judges.

Attorneys say the decision in McKinney's case could affect other Arizona death row inmates who could challenge the test used in evaluating the mitigating factors considered during sentencing. But it's unclear whether the ruling would affect death penalty cases from other states.

Jordon Steiker, a law professor at the University of Texas who filed a friend-of-the-court brief supporting McKinney's position, said he doesn't think the McKinney decision will have much of an effect on cases outside of Arizona.