I think Justice was carried out properly, Just wish his co-conspirator had gotten death penalty too instead of life.
You have to think that it was not one eye wittiness that could have been mistaken to convict him, It was lots of physical evidence and other things that put the pieces of the puzzle (his crimes) together.
It also was NOT a heat of passion or sudden snap that brought about this crime spree, he and his co-conspirator had many chances to stop their actions but they didn't. They planned for quite some time, got equipment, not just the guns and ammo but a car that they could rig up as a sniper hide. Then they traveled around the country and shot strangers in several states over a period of time. They also left a note at the scene as a taunt to mark their kill.
Military service can be hard on many individuals in combat zones and it causes problems sometimes adjusting back to stateside living but you don't see many with PTSD that resort to long term planned shootings of civilians over a wide area.
The death penalty gives society a sense of payback for a wrong so we don't have lynch mobs committing "street justice" or family vendettas that go on for generations. It does conflict somewhat with the idea of rehabilitation but it should be metered out in those most heinous of cases where once a person is accurately convicted it is carried out because that person needs to pay the ultimate price for such a wrongful act and the odds are they can't be rehabilitated and society should not have to house them for life especially when their victim was sentenced to death by the perpetrator.
Just my .02 though.
And lastly as they used to say, "The death penalty cuts down on second offenders."