( CNN ) A judge has vacated the conviction of a 14-year-old boy who was executed for allegedly killing two girls some 70 years ago in South Carolina . The judgment against George Stinney , the youngest person to be executed by an American state since the 1800s , effectively exonerates the boy , said family attorney Matt Burgess . A black teen in the Jim Crow South , Stinney was accused of murdering two white girls , ages 7 and 11 , as they hunted for wildflowers in Alcolu , about 50 miles southeast of Columbia . Stinney , according to police , confessed to the crime . No witness or evidence that might vindicate him was presented during a trial that was over in fewer than three hours . An all-white jury convicted him in a flash , 10 minutes . `` Given the particularized circumstances of Stinney 's case , I find by a preponderance of the evidence standard , that a violation of the Defendant 's procedural due process rights tainted his prosecution , '' wrote Circuit Judge Carmen Tevis Mullen in her decision , dated Tuesday . She said that sentencing a 14-year-old to the death penalty constitutes cruel and unusual punishment . Earlier this year , attorneys for Stinney 's family had asked for a new trial , saying the boy 's confession was coerced and that Stinney had an alibi , his sister , Amie Ruffner , who claims she was with Stinney when the murders occurred . Ruffner , Stinney 's sister , told CNN affiliate WLTX that she and Stinney saw Betty June Binnicker , 11 , and Mary Emma Thames , 7 , the day they died . Stinney and Ruffner were tending to their family 's cow near some railroad tracks close to their home . `` They said , 'Could you tell us where we could find some maypops ? ' `` Ruffner recalled . `` We said , 'No , ' and they went on about their business . '' The girls were found the next day in a water-logged ditch with injuries to their head . Mary had a 2-inch laceration above her right eyebrow and a vertical laceration over her left , according to a 1944 medical examiners ' report . Ruffner told WLTX , police took Stinney and another of her brothers away in handcuffs while their parents were not at home . One brother was released , she said , while Stinney faced police questioning without his parents or a lawyer . The police `` were looking for someone to blame it on , so they used my brother as a scapegoat , '' Ruffner said . CNN 's David Mattingly contributed to this report .
Stinney was executed for killing two girls some 70 years ago in South Carolina . A judge rules a violation of his due process rights `` tainted his prosecution '' and he is sentenced to death by lethal injection.