DALLAS (AP) - The ringleader of the biggest prison escape in Texas history was sentenced to death Wednesday for killing a police officer while on the run. George Rivas had pleaded with jurors to give him the death penalty so wouldn't have to live ``like an animal in prison.'' Rivas, 31, was the first of the seven escapees to be tried in the Dec. 24 shooting death of Irving police Officer Aubrey Hawkins. Defense attorneys have been trying to get Rivas a life sentence, saying he never intended to murder Hawkins. But as the penalty phase wrapped up Wednesday, Rivas in a surprise twist asked jurors to give him a death sentence. ``What you call the death penalty, I call freedom,'' he said. ``I can finally be free. I'm telling you right now I don't want another life sentence.'' Speaking haltingly and emotionally, Rivas said: ``I don't want to just exist anymore like an animal in prison.'' A day earlier, Rivas testified that he never intended to kill Hawkins and took pains to limit bloodshed in the prison escape. His death wish was cited by both sides during closing arguments. ``Ladies and gentlemen, grant him his wish and justice will be done in this courtroom today,'' prosecutor Bill Hill said. Defense lawyer Wayne Huff said a life sentence would be worse than death for Rivas, who would be locked 23 hours a day in an isolation cell. In arguing for the death penalty, prosecutors tried to demonstrate that Rivas was a lifelong felon who showed no mercy when he repeatedly shot Hawkins and ran over him with a vehicle. Rivas himself confessed to the crime. Evidently deciding they had nothing to lose, Rivas' attorneys let him take the stand. He spoke gravely when he took full responsibility for Hawkins' murder. He also said he planned the getaway because ``I wasn't going to die an old man in prison.'' Jurors found Rivas guilty of capital murder Aug. 21. They had two punishment choices: lethal injection or life imprisonment with the possibility of parole in 40 years.