The Mississippi Supreme Court on Monday upheld the conviction of white supremacist Byron De La Beckwith in the 1963 assassination of civil rights leader Medgar Evers.
The court said the 31-year lapse between the ambush slaying and Beckwith's conviction did not deny him a fair trial.
"Miscreants brought before the bar of justice in this state must, sooner or later, face the cold realization that justice, slow and plodding though she may be, is certain in the State of Mississippi," Justice Mike Mills wrote.
The ailing Beckwith, now 77, stood trial twice in 1964, but both juries deadlocked. The case was resurrected, and he was convicted in 1994.
Evers, field secretary for the Mississippi NAACP, was killed in his driveway by a sniper.
Beckwith contended that he was miles away at the time, but his fingerprint was found on the scope of a rifle believed to be the murder weapon.