A 71-year-old Louisiana inmate whose case led to a landmark U.S. Supreme Court decision on juvenile-offender sentences was denied parole Monday, more than a half-century after he killed a sheriff's deputy at age 17.

A three-member panel from the state parole board voted 2 to 1 to keep Henry Montgomery imprisoned. The hearing was his first chance at freedom since his conviction decades ago and a vote to free him would have had to be unanimous. Montgomery now must wait another two years before he can request another parole hearing.

The Supreme Court's January 2016 decision in Montgomery's case opened the door for roughly 2,000 other juvenile offenders to argue for their release after receiving mandatory life-without-parole sentences.

Montgomery has served 54 years in prison for shooting East Baton Rouge Parish sheriff's deputy Charles Hurt in 1963, less than two weeks after Montgomery's 17th birthday. Last June, a state judge who resentenced Montgomery to life with the possibility of parole called him a "model prisoner" who seemed to be rehabilitated.

Montgomery's lawyers said he has sought to be a positive role model for other prisoners, serving as a coach and trainer for a boxing team he helped form at Louisiana State Penitentiary at Angola.

But the two parole board members who voted against Montgomery questioned why he hadn't accessed more prison programs and services that could have benefited him. One of the panelists, Kenneth Loftin, also said he was disappointed in some of Montgomery's statements during the hearing but didn't elaborate.

James Kuhn, the other board member who voted against Montgomery, noted that the Louisiana Sheriffs' Association submitted a statement opposing his release.

"One of the things that society demands, and police officers certainly demand, is that everyone abide by the rule of law. One of the rules of law is you don't kill somebody, and when you do there's consequences," Kuhn said.

Republicans say they’ll go to federal court this week to try to block new court-ordered boundaries of Pennsylvania’s congressional districts from remaining in effect for 2018’s elections.

Top Senate Republican lawyer Drew Crompton said Monday a separation of powers case will form the essence of the GOP’s argument. Crompton won’t say whether Republicans will go to a district court or the U.S. Supreme Court or what type of legal remedy they’ll seek.

But the case will involve making the argument the U.S. Constitution gives state legislatures and governors, not courts, the power to draw congressional boundaries.

Earlier this month, the U.S. Supreme Court wouldn’t stop the state court’s order to redraw congressional districts. Democratic Gov. Tom Wolf calls the new map an effort to remedy the state’s unfair and unequal congressional elections.

Democratic Pennsylvania Gov. Tom Wolf is applauding the new boundaries of congressional districts being imposed by the state Supreme Court.

Wolf said in a statement Monday that Pennsylvanians “are sick and tired of gerrymandering.” He calls the court’s map an effort to remedy the state’s unfair and unequal congressional elections.

Wolf had backed the Democratic-majority state high court’s ruling last month to throw out Pennsylvania’s district boundaries. Republicans have won 13 of Pennsylvania’s 18 seats in three elections under the invalidated map, although statewide elections are often closely contested.