The Texas Supreme Court ruled on Friday that a legislative subpoena cannot interfere with an execution scheduled by the judiciary, emphasizing the importance of separation of powers. The ruling centers on the case of Robert Roberson, who was convicted in 2003 of killing his two-year-old daughter, Nikki Curtis, through shaken baby syndrome—a diagnosis now widely debated.

The case drew national attention when, on October 16, a day before Roberson’s scheduled execution, a bipartisan Texas House committee issued a subpoena requiring him to testify about his case and its implications for article 11.073 of the Texas Code of Criminal Procedure, which allows courts to free individuals based on new scientific developments. The subpoena temporarily halted the execution, raising unprecedented legal questions over whether the legislature could interfere with the judiciary’s authority to carry out a death sentence.

The Texas Supreme Court, in a 31-page opinion written by Justice Evan Young, concluded that while legislative investigatory powers are robust, they do not extend to disrupting the judiciary’s enforcement of final judgments. “The committee’s authority to compel testimony does not include the power to override the scheduled legal process leading to an execution,” Young wrote.

The court acknowledged that the committee could have sought Roberson’s testimony before the death warrant was issued, or even afterward, without disrupting the process. By issuing the subpoena at the last minute, the legislature intruded on the judiciary’s authority to schedule executions and the executive branch’s clemency powers.

The court’s decision allows Texas authorities to reschedule Roberson’s execution, but not before a three-month delay, providing an opportunity for the House committee to hear Roberson’s testimony. The decision also pointed out the importance of cooperation between branches of government, stating that the executive branch must accommodate the legislature’s lawful requests for testimony.

Lawmakers remain divided on the case’s implications. State Representatives Joe Moody (D) and Jeff Leach (R) praised the court for recognizing the validity of the subpoena and expressed hope for a cooperative resolution. The Court “strongly reinforced our belief that our Committee can indeed obtain Mr. Roberson’s testimony and made clear that it expects the Executive Branch of government to accommodate us in doing so,” they said in a joint statement.

Roberson’s defense team continues to advocate for clemency, citing new medical evidence that challenges the shaken baby syndrome diagnosis and points to other potential causes of Nikki’s death. His lawyer, Gretchen Sween, urged Texas authorities to reconsider proceeding with the execution, stating, “The ancillary benefit to Mr. Roberson of staying his execution hopefully gives time for those with power to address a grave wrong to see what is apparent to anyone who gives the medical evidence fair consideration: his daughter Nikki’s death was a tragedy not a crime; Robert is innocent.”