The Texas Supreme Court has ruled that lawmakers cannot stop executions through a legislative subpoena after the execution of Robert Roberson was delayed last month.

Texas lawmakers exceeded their power when they intervened last month to stop the execution of Robert Roberson by summoning him to testify, the court found.

The state’s highest civil court ruled that legislators can’t use subpoenas to block death row inmates’ executions, but suggested there’s still time for Roberson to testify before a Texas House panel.