The federal government is set to resume executions with the drug pentobarbital, despite concerns it might violate the Eighth Amendment.
"This is not a happy night. This is the end of a horror story," the McLennan County District Attorney said.
The inmates argued that the state has the means to orchestrate their deaths by firing squad.
Rodney Scott Berget was executed by lethal injection for a 2011 murder during a failed attempt to escape from jail.
Three days before his scheduled execution, convicted killer Edmund Zagorski convinced Tennessee's Supreme Court to spare him death by lethal injection in favor of the electric chair.
Carey Dean Moore has been on death row for almost 40 years.
Bible, 66, was executed on Wednesday in Huntsville.
Oklahoma is one of many states attempting to move beyond lethal injection as a method of execution.
The ACLU said that in attaining a DEA registration to import drugs, Nebraska listed a licensed prison pharmacy that's not located where the drugs will be used for the executions.
Capital punishment cases are down but five of the 23 executions this year still highlight the arguments of those who oppose the death penalty.
An opioid at the heart of America's drug epidemic will be used for death row executions in Nevada and Nebraska if the never-before-tried combination of drugs is approved.
Ledelle Lee and Kenneth Williams received communion, while Marcel Williams and Jack Jones had more elaborate requests.
The double execution took place days after the state ended a nearly 12-year hiatus on executing prisoners on death row.
Staring in January, Ohio will again begin executing inmates after halting the practice in 2014.
The state was unsuccessful when it first tried to execute Romell Broom in 2009.
Texas to execute Coy "Elvis Wayne" Wesbrook after spending 17 years on death row.
Georgia is slated to execute a former sailor on Wednesday for the murder and dismemberment of a fellow shipmate 24 years ago.