AUSTIN, Texas >> The Texas Supreme Court on Friday ruled that a legislative subpoena cannot stop an execution after Republican and Democratic lawmakers who say Robert Roberson is innocent used the novel maneuver to pause his execution at the last minute.

The ruling clears the way for Roberson’s execution to move forward, weeks after a bipartisan group of state House lawmakers bought him more time by subpoenaing Roberson as he waited to be taken to the nation’s busiest death chamber. Roberson was sentenced to death in 2003 for killing his 2-year-old daughter, Nikki Curtis. He would be the first person in the United States to be executed over a conviction tied to “shaken baby syndrome,” a diagnosis that has been questioned by some medical experts.

A new execution date for Roberson has not been set, but it is certain to proceed unless Republican Gov. Greg Abbott grants a 30-day reprieve. Abbott did not move to do so before Roberson’s original execution date and his office challenged the subpoena tactic used by lawmakers, accusing them of overstepping their power.

The state’s all-Republican high court agreed, ruling that “under these circumstances the committee’s authority to compel testimony does not include the power to override the scheduled legal process leading to an execution,” wrote Republican Justice Evan Young. The Supreme Court, which handles civil matters, made clear it was not ruling on the merits of whether Roberson was guilty or innocent.