WASHINGTON (CN) - The Supreme Court refused to block a Thursday execution for an Alabama man who claims the state unconstitutionally sentenced him to death when he was 18. 

Casey McWhorter asked the justices to pause his Nov. 16 execution to decide if Alabama had unconstitutionally sentenced him to death by refusing to provide him with a jury of his peers. The high court denied his stay applications and petitions for certiorari. There were no noted dissents from the order or any explanation for the ruling. 

When McWhorter was barely 18, he shot Edward Lee Williams 11 times, killing him. The murder happened during a home robbery committed by McWhorter and two others who were 15 and 16 years old. 

After being hospitalized for a suicide attempt, McWhorter confessed his crime to the police. McWhorter was sentenced to death for the crime, however, he told the Supreme Court his sentence was unconstitutional because Alabama did not try him under a jury of his peers. 

"Alabama's treatment of 18-year-olds is unconstitutional," Benjamin Rosenberg, an attorney with Dechert representing McWhorter, wrote. "If 18-year-olds are competent to be tried as adults and subject to capital punishment, there is no rational reason for them to be excluded from state jury service." 

Although all his prior attempts at post-conviction relief failed, McWhorter urged the Supreme Court to review his constitutional claims, arguing his Sixth, Eighth, and Fourteenth Amendment rights were violated. 

McWhorter says Alabama does not give equal treatment to 18-year-olds under the law. They are considered juveniles and can not serve on juries, however, 18-year-old criminal defendants can face the adult sentence of capital punishment. 

"By systematically excluding 18-year-olds from jury venires, Alabama deprives criminal defendants of their right under the U.S. Constitution to a jury drawn from a fair cross-section of the community, and it deprives all 18-year-olds of their right to serve on juries," Rosenberg wrote. "And if 18-year-olds are juveniles, as Alabama law has deemed, then they should not be eligible for the death penalty." 

Alabama said the high court's relief was not necessary because McWhorter's appeal concerned no emergency matter. The state said McWhorter should have raised the constitutional claims in his petition decades ago, not immediately before his execution date. 

"Because he declined to raise those claims at the right time and in the right forum, instead waiting until the eleventh hour to file a time-barred successive habeas petition (directly in the Alabama Supreme Court), McWhorter is not entitled to the equitable remedy of a stay," James Roy Houts, Alabama assistant attorneys general, wrote. 

The Supreme Court's decision not to pause McWhorter's execution came two hours after his execution window began. Alabama will have until Friday morning to carry out his death sentence. 

Source: Courthouse News Service