Hernandez, 52, was pronounced dead at 6:23 p.m. CDT, shortly after receiving a lethal injection for the March 1985 shooting death of 20-year-old Victor Cervan, one of five Mexican nationals who had been robbed near New Baunfels.
Hernandez was within minutes of execution in March when Gov. Rick Perry granted him a 30-day stay at the request of San Antonio police who wanted to question him about unsolved slayings in the city.
At a news conference Tuesday, San Antonio police said Hernandez had been linked positively to two more murders and was a suspect in at least a third. They said the death row inmate had helped them clear the cases that were 18 to 20 years old.
In his final statement, Hernandez thanked five friends who were witnesses at his execution.
"Everybody will be all right, because y'all are going where I am going," he said. "Remember what I said, I want to see you all where I'm going. I want to give you thanks. God, come and do your will. I'm ready warden."
Hernandez lost his left leg to complications from diabetes last summer and he used to walker and wheelchair. He had requested an artificial limb so he could walk to his execution, but prison officials said doctors could not fit him with the device because of a recurring infection in the wound on his amputated leg.
In March 1985, Hernandez and another man had been hired by Cervan and four other Mexican nationals to drive them to Denton in North Texas for $150 each. They were instead taken to a secluded place near New Braunfels where they were robbed and then shot.
Cervan died of his gunshot wounds at a local hospital but the other victims survived and later identified Hernandez and his accomplice.
Hernandez was the 10th convicted killer executed this year in Texas. Curtis Moore is scheduled for execution Wednesday in the first of eight executions scheduled in May. Texas has carried out 266 executions since restoration of the death penalty in 1982.