LITTLE ROCK, Ark. (AP) _ A man who killed a state trooper was executed by lethal injection Thursday night after Gov. Bill Clinton denied him clemency.

Also Thursday, Texas executed an inmate for killing a store owner in a holdup 14 years ago.

Steven Douglas Hill, 25, the youngest of 35 inmates on Arkansas' death row, was pronouced dead at 9:10 p.m., eight minutes after he was injected with the drugs at the prison in Varner, about 70 miles southeast of Little Rock.

''I ask for my family's forgiveness, for the pain I caused, and Officer Klein's family,'' Hill said as he lay strapped down in the execution chamber. ''The children shouldn't have to be raised without a father. I'm ready to go.''

Clinton returned to Little Rock on Wednesday night to review his case, but denied the clemency request Thursday afternoon. The U.S. Supreme Court denied an appeal filed Thursday by Hill's attorney, Mark Cambiano.

Cambiano had taken the case to the Supreme Court after the 8th U.S. Circuit Court of Appeals at St. Louis voted 8-1 Thursday to reject an appeal by Hill, condemned for the 1984 shooting death of an Arkansas State Police investigator. As governor, Clinton has scheduled executions for 26 prisoners, of whom four have been executed. He has never granted clemency for a death row inmate.

''We do support the death penalty for cop killers, multiple murderers and drug kingpins,'' Clinton said earlier this year.

Death penalty opponents claim Clinton's stance on capital punishment is dictated by politics.

''He's not dying to be president, but he is killing to be president,'' said Carrie Rengers of the local chapter of Amnesty International.

A black, brain-damaged inmate was executed Jan. 24 in Arkansas, drawing criticism from death penalty foes and black leaders. A man who killed a police officer and a mass murderer were executed in June 1990.

About 25 people, including one person dressed as the Grim Reaper, protested Wednesday outside the gates of the Governor's Mansion in Little Rock.

Hill was an 18-year-old state inmate in 1984 when he and a fellow prisoner, Michael Anthony Cox, escaped while on a work detail. They tied up the occupants of a central Arkansas home, stealing weapons and a truck before heading to a nearby house. Police surrounded the house and investigator Robert Klein was fatally shot with a shot gun.

Hill, whose confession was videotaped by police, was sentenced for the murder. Cox was sentenced to 86 years for related crimes. Cox later said he - not Hill - pulled the trigger.

State prosecutors, a federal judge and the state parole board have said they don't believe Cox, who they said changed his story several times.

Hill apologized to Klein's family in a hearing before the parole board last month.

''I'd just like to tell the family of officer Klein that whoever pulled the trigger, I'm the one responsible,'' Hill told the state parole board.

Hill's family and sympathizers said the inmate is a victim of a tormented and lonely childhood.

They said his troubles started at age 12 when he was hit in the eye by a stray bullet while shooting at rats in a barn with his brother-in-law. His family said Hill never responded well to the taunting he received for wearing an eye patch.

Hill, a frail teen, was raped repeatedly when imprisoned for breaking and entering and criminal mischief, said a Catholic priest who befriended Hill in prison. The rapes prompted Hill to escape, the Rev. George Tribou said.

In Huntsville, Texas, Justin May, 46, died by injection after the U.S. Supreme Court rejected late-hour appeals in which he argued he had been framed.

May's execution was witnessed by his sister and a woman he had recently married by proxy.

''I just want to tell them that I love them and appreciate all the support,'' May said in a final statement.

After the lethal drugs were administered, May went into a coughing spasm, groaned and gasped, lifted his head from the gurney and would have arched his back if he had not been strapped down.

May became the 48th person executed in Texas since the state resumed carrying out capital punishment in 1982. The total is the nation's highest.

He was sentenced to die for 1978 shooting of Jeanetta Murdaugh, 43, in Freeport. Her husband also was slain in the robbery at the couple's auto parts store, but May wasn't tried in his death.