Huntsville (US), Sep 26 (AP) A Texas inmate who claimed he was intellectually disabled was executed for fatally stabbing his two stepsons during a 2007 attack in their Dallas home that also left his wife dead.

Robert Sparks received a lethal injection at the state penitentiary in Huntsville on Wednesday for the slayings of 9-year-old Harold Sublet and 10-year-old Raekwon Agnew.

Sparks, 45, became the 16th inmate put to death this year in the U.S. and the seventh in Texas.

"I am sorry for the hard times. And what hurts me is that I hurt y'all ... even y'all, too," Sparks told his relatives and friends who watched through a death chamber window, turning his head at one point to address family members of his victims who sat behind a separate window.

As the lethal dose of pentobarbital began, he said, "I love you all" and then added, "I feel it." He took two deep breaths almost immediately, snored three times and then all movement ceased. He was pronounced dead 23 minutes later.

Seven more executions are scheduled this year in Texas, the nation's busiest capital punishment state.

Prosecutors said the attack in September 2007 began when Sparks stabbed his wife, 30-year-old Chare Agnew, 18 times as she lay in her bed. Sparks then went into the boys' bedroom and separately took them into the kitchen, where he stabbed them. Raekwon was stabbed at least 45 times.

Sparks then raped his 12- and 14-year-old stepdaughters, authorities said.

"The day when the situation was going on, he said that we wouldn't make it," a woman who is one of Sparks' surviving victims said after witnessing the execution. "Twelve years later, we're both standing here. ... I want him to know we're not suffering. We're hurt emotionally but physically we're fine."

She added that Sparks being put to death "kills the nightmare."

The US Supreme Court declined a request by Sparks' attorneys to stop the execution.

They had alleged his trial jury was improperly influenced because a bailiff wore a necktie with an image of a syringe that showed his support for the death penalty. Sparks also alleged a prosecution witness at his trial provided false testimony regarding his prison classification if a jury chose life without parole rather than a death sentence. (AP)

(This is an unedited and auto-generated story from Syndicated News feed, LatestLY Staff may not have modified or edited the content body)