"Next, in the US there is a US Supreme Court case called Tennessee v. Garner. It was settled a long, long time ago and describes when a law officer can justifiably shoot a person. Mere fleeing is not one of those times (though I have to admit, I have forgotten the fine details of this case and can't recall if the border patrol agents were in fear for their lives or not)."

This was a large part of their trouble. But it was moreso that they subsequently lied and covered up details about the shooting. As a mitigating factor, it appears that a superior asked them to do so. Their sentence is so long because it fell within mandatory minimum sentencing guidelines for firearm crimes.

However, the right wing and the group of congresspeople protesting are probably correct in that officers of the law in the line of duty were not meant to be covered by a poorly-written law, and there ought to be a separate analysis of circumstances in their case. Ramos and Compean argued compellingly that they had been in danger, but the distance at which the suspect was shot and the fact that it was in the back was impossible for the jurors to overlook.

In this type of a case, apparently, the convicted normally have to serve their sentences before getting a pardon. As such, this may come up during Obama's 2nd term or an new president, whichever comes next. As I said, lots to argue on both sides of this case. This is one where it would be pretty silly to dismiss the right wing arguments just because they come from there.