I cringe at the usage of guns in the US by law enforcement. We could be using tasers, instead. We could have systems far better then tasers.
I think a lot of this is because of the gun culture here.
Killing these guys is extremely damaging for investigative purposes.
I would agree with your sentiment about how law is more better upheld without killing suspects or convicted perpetrators.
A lot of Americans would disagree with me. But that argument comes down to them arguing people making this argument are "soft of heart", and they are "hard of heart" -- where "hard of heart" they value as a virtue.
Ironically, it is probable the majority of those who would make this argument go to church every Sunday. Yet, the virtue of being "soft in heart" versus the vice of being "hard in heart" does not seem to sink in.
On tinfoil hat scenario:
The evidence seems strong this is a clear case where these guys were succumbed by a violent religious-political ideology. Enough so that Russia took the time to identify them and keep track of them on these very issues. They also took the time to work with our authorities to ensure their business was accounted for.
And, like many of these cases, the ball is dropped. I am seeing, in the media, this pressure is not being put on these suspects.
There are claims like "they worked alone", and "this was reasonable that they dropped off the radar". It really is not, at all, reasonable.
Could they have been setup? Anything is possible. In the nineteenth century, one of the ways frustrated policing agencies dealt with "saboteurs" was by setting them up. It is hard and frustrating to not try and entrap them.
But there are laws which enable cops to surveil legitimately suspicious suspects like this. There are laws which can get them arrested for being involved in these sorts of conspiracies.
Really, like in many of these cases, including 911, the suspects went overseas and to terrorist training facilities.
If that is not the criteria for a suspect, then what is? That they are Democrat? That they belong to the Tea Party? That they are political opponents to some powerful members of congress?
So, I see viability for conspiracy there, but not so much with these two actors.
Unless they were undercover agents, or didn't really have a violent bone in their body but just found some girl at an terrorist training facility.... and we can see from their actions this does appear not to be the case, at all.