Image copyright Reuters Image caption Fuller was convicted of killing his neighbours during a 2003 shooting

A Texas man who said he wanted to be put to death for killing a couple in 2003 has been executed, after telling his lawyer to drop appeals.

Barney Fuller, 58, pleaded guilty to capital murder for killing his neighbours during a shooting rampage.

Fuller avoided eye contact in the death chamber with witnesses, including two children of the slain couple.

He blurted out a comment to officials administering the lethal injection and took longer than expected to die.

In a hearing earlier this year, he said he had no challenges to his death sentence and was "ready to move on".

Asked on Wednesday evening if he had any final statement, Fuller responded: "I don't have anything to say. You can proceed on, Warden Jones."

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Fuller took a deep breath as officials injected a lethal dose of pentobarbital into each arm.

"Hey, you fixin' to put me to sleep," he said.

After a couple of breaths, Fuller began snoring and all movement stopped within 30 seconds.

He was pronounced dead 38 minutes later, at 19:01 local time, taking longer than expected to die.

Texas Department of Criminal Justice spokesman Jason Clark explained the extended time by saying: "Each person is unique in how his body shuts down."

Fuller's lethal injection was Texas' seventh execution this year. The Lone Star state carries out the most executions in the US.

His death marks the longest gap between executions in Texas since 2008, when the US Supreme Court considered whether lethal injection was unconstitutional.

He was arrested and charged 13 years ago for the murder of Nathan Copeland, 43, and his wife, Annette, 39, at their home in Lovelady, about 100 miles north of Houston.

He fired 60 shots into their home before breaking in and opening fire on the couple and their children, injuring their 14-year-old son.

The couple's 10-year-old daughter was able to escape when Fuller could not turn on the light in her bedroom.

Fuller and the Copelands had a longstanding dispute that culminated when Fuller was summoned to court in 2003 on a charge that he threatened the family.

Two days later, he killed the couple.

Last year, Fuller wrote to his attorney saying that he wanted proceed with the execution.

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"But I also really do not care and do not want to go on living in this hellhole," he wrote. "Do not do anything for me which will prolong my appeals and time here on Texas death row."

At hearing in the spring, a federal judge ruled Fuller competent to waive his right to appeal.

"What's the point of sentencing someone to death, you know, if you're not going to carry on through with what you ordered," he said at the hearing.

Fuller's execution is the 16th this year in the US.