Texas executed a convict Wednesday, despite proof of a mental disorder developed in his childhood, prison authorities from the southern US state said.
Yokamon Hearn, a 34-year-old African American, was sentenced to death at age 19 for killing a white man in a carjacking. Hearn was pronounced dead by lethal injection at 0034 GMT Thursday.
For the first times, Texas executioners administered one single injection of pentobarbital. Several states are using the new injection, after one of the three traditional injections used in executions had run out of stock.
"I would like to tell my family that I love (you), and I wish," Hearn said in his last statement, trailing off before a final, "Well. I'm ready."
On death row for 14 years, Hearn was diagnosed with mental disorders related to fetal alcohol syndrome, caused by his mother's alcohol abuse during pregnancy, and severe neglect as child. Hearn had suicidal thoughts at age 10 and suffered brain damage, according to Texas-based criminal justice system advocacy group StandDown.
The US Supreme Court rejected Hearn's final appeal Wednesday, shortly before the execution. A Texas appeals court rejected a move to retry his case for the "ineffective assistance" of trial counsel Monday.
Hearn's legal representation failed to compile the evidence necessary to prove his mental disorder and preclude him from the death penalty.
The US Supreme Court prohibited the execution of mentally handicapped convicts in 2003 to avoid the risk of arbitrary executions.
Hearn was sentenced to death in 1998 for kidnapping the victim, 26, at a car wash, later shooting him 12 times in the head and chest, according to a court document.
A UN human rights official in Geneva urged the US to halt the execution Tuesday.
"It is a violation of death penalty safeguards to impose capital punishment on individuals suffering from psychosocial disabilities," said special rapporteur Christof Heyns.