Texas death row inmate Robert Roberson sat praying in a cell Thursday night, just feet from the execution chamber where he was set to die by lethal injection for the “shaken baby” death of his toddler.

Roberson was scheduled to become the first person in the country to be executed based on "shaken baby syndrome" evidence, until Texas lawmakers subpoenaed him to testify.

A Texas man this week could become the first person executed in the U.S. under a murder conviction tied to the diagnosis of shaken baby syndrome.

HOUSTON — The Texas Board of Pardons and Paroles on Wednesday denied a request for clemency for Robert Roberson, who could be the first person in the U.S. executed for a murder conviction tied to the diagnosis of shaken baby syndrome.

Gloria Rubac, left, an anti-death penalty activist, speaks during a protest outside the prison where Robert Roberson is scheduled for execution at the Huntsville Unit of the Texas State Penitentiary, Thursday, Oct. 17, 2024, in Huntsville, Texas. (AP Photo/Michael Wyke) AP

A Texas judge has blocked the execution of the first man to be put on death row in the US for murder charges related to "shaken baby syndrome", less than two hours before the execution was due to be carried out.