The US state of Texas on Wednesday executed a man for the murder of an 84-year-old woman who was weighted down with a cinder block and thrown into a river, a prison official said.

Danielle Simpson, 30, had decided this summer to drop all his appeals in the case, effectively volunteering himself for execution, but recently changed his mind and allowed his lawyers to seek a suspension.

Simpson was declared dead at 6:32 pm, nine minutes after receiving a lethal injection, according to Texas Department of Criminal Justice official Michelle Lyons.

Simpson, age 20 at the time of the murder in 2000, his wife Jennifer, 17, and his brother traveled to the home of Geraldine Davidson in Simpson's home town of Palestine, Texas, the department said in a statement.

Local news reports said she returned home to catch them robbing her house. They taped her mouth shut, bound her hands and feet and put her in the trunk of her vehicle which they drove to the Nueces River, the department
said.

Evidence presented at trial showed that Simpson beat Davidson before tying a cinder block to her feet and throwing her into the river where she drowned.

His accomplices were sentenced to prison.

Simpson offered a brief final statement before witnesses, who included his father and two sisters as well as Davidson's three children.

"Yeah, I want to tell my family I love y'all," said Simpson. "I'm gonna miss y'all. I'm ready, ready."

With Simpson, Texas has now executed 22 prisoners this year and 445 since the US Supreme Court reinstated the death penalty in 1976, the most of any US state. Another execution is scheduled for Thursday.