I would hope he lives and faces trial in Texas!!
I doubt that he will.
He committed murder on a Federal Reservation. He was a serving Army Officer that shot serving Army personel.
He will be tried in a military court and serve out his sentence in a Federal prison.
He could possibly stand trial for treason but a don’t see that happening in Obama’s army.
He will most likely be facing court-martial for a number of spcifications under the UCMJ. Although the military hasn't executed anyone since 1961, Reagan reinstated the military death penalty back in 1984, with a few changes. Bush, just last year, was the first President to approve a military execution since Eisenhower in '58 (for the execution carried out in '61). Sadly, the execution that Bush approved was for a serial killer/rapists who's last crimes were in 1987 or 1988. So, it takes some time, and he's still not dead has his sentence was stayed pending further appeal just weeks before his scheduled execution.
The Akbar case from 2005 is pending it's final mandatory appeal, which should be completed in 2-6 months, which will put it in Obama's court to either approve or deny. Then that decisions, like the 87 case, could be appealed as well.
In short, if he were to be tried under Texas law, which isn't impossible but VERY, very unlikely, he'd be dead probably within 5 years. FWIW.