Prosecutors said Michael Rodriguez fired one of five weapons used to kill 29-year-old rookie officer Aubrey Hawkins, who was trying to stop the Christmas Eve 2000 robbery in Irving.
Defense attorneys had maintained that Rodriguez, 39, who was convicted last week, had no intent to kill. They immediately filed a notice of appeal.
The inmates led authorities on a nationwide manhunt before six were caught in Colorado about six weeks later; one committed suicide rather than face capture.
Two other escaped convicts, George Rivas and Donald Keith Newbury, have also been convicted and sentenced to death. The remaining three also face capital murder charges.