Texan authorities hail execution drug that critics say causes agony

Prisoner who was said to be mentally impaired is first to be killed using controversial method

Authorities in Texas have defended the state's first execution of a death row inmate using a single lethal injection of the sedative pentobarbital, instead of the cocktail of three drugs used in the past, saying it went "without incident".

The prisoner, 33-year-old Yokamon Hearn, who had been convicted of carjacking and fatally shooting a Dallas area stockbroker in 1988, was declared dead at the Huntsville penitentiary on Wednesday, 25 minutes after the sedative was injected into his body.

Hearn was executed in spite of a last-minute appeals to the Supreme Court and pleas for a stay from anti-death penalty advocates because of concerns over the use of the single drug. Opponents of the death penalty say inmates die slower and suffer more by the single-drug method. The case had also been controversial because of claims by Hearn's lawyers that he had suffered mental impairment because of alcohol abuse by his mother when she was carrying him before birth.

Texas and three other US states – Ohio, Arizona, Washington and Idaho – have been forced into changing the drug mix in the execution chamber after one of the three, thiopental sodium, was taken off the market in 2010. The European Union had placed a ban on the export of the drug to the US, precisely because the primary customers were states exercising capital punishment. Hearn was the first inmate to be killed in Texas using the method. The French government joined others yesterday criticising Texas for Hearn's execution. "France condemns the execution of a citizen of the United States who suffered from mental problems," a foreign ministry spokesman said, adding that "this execution was contrary to recognised international guarantees." A spokesman for the Texas Department of Criminal Justice said the execution had been "carried out without incident" in spite of fears that the administration of pentobarbital might present risks.

Authorities did not address concerns held by opponents of the death penalty that the single drug method could increase the pain suffered. He added: "The one-drug protocol has been adopted by several states, and has been upheld as constitutional."

Among witnesses to the execution were family members of the victim, Frank Meziere, who was 23 when he was forced into his Ford Mustang by Hearn and three accomplices and taken to open ground outside Dallas and killed with 10 bullets to the head. "We did not come today to view this execution for revenge or to even the score," the family said afterwards. "What this does is give our family and friends the knowledge that Mr Hearn will not have the opportunity to hurt anyone else." On Tuesday, Georgia said it too was switching to using pentobarbital only in its execution chamber. It postponed an execution scheduled for Wednesday to prepare to switch to the single drug.

Hours before the killing of Hearn, the UN special rapporteur on arbitrary executions in Geneva, Christof Heyns, appealed to Texas to reconsider. "There is evidence to suggest that he… suffers from psychosocial disabilities," he said, noting that experts had testified that the alcohol abuse by his mother had caused him to be affected by "structural brain dysfunction".

But Jason January, the former assistant district attorney who prosecuted Hearn, said to stop the punishment because of fetal alcohol syndrome "would be a free pass for anyone whose parents drank". He added: "A lot of people have tough backgrounds and work their way out and don't fill someone's head with 10 bullets."

Crime scene: The path to death row

Yokamon Hearn was 19 years old when he committed the crime for which he would eventually be sentenced to death. The victim, 23-year-old Frank Meziere, was cleaning his car when Hearn and his friends forced him to drive at gunpoint to an industrial area in a south Dallas neighbourhood, where he was shot 10 times in the head.

Hearn pleaded not guilty at his 1998 trial, but a jury took only 50 minutes to convict him of murder carried out in the course of a kidnapping – a capital offence.

In one appeal, Hearn's lawyers argued that his mother drank alcohol when she was pregnant, leaving him with mental impairments that disqualify him from execution. But tests showed Hearn's IQ was too high for him to be considered mentally impaired. In another, his lawyers claimed the trial attorneys failed to investigate his troubled childhood.

State attorneys contested both appeals, arguing that information about Hearn's background had been "thoroughly investigated and addressed at trial".

When asked if he wanted to make a final statement, Hearn said: "I'd like to tell my family that I love y'all and I wish y'all well. I'm ready."