Were they lawbreakers if there was no trial? I'd say that you're innocent unless proven guilty.
I don't know how in the US, but in Europe it is illegal to write publicly "Joe Average, a murderer", if the person had no trial, yet. Regardless of the widely available proofs.
After the fact - once the jury decided you are innocent - it is extremely hard to get your good name back.
Nope. The beauty of free speech is that it's only illegal if it's either untrue or you cant prove it (which are in essence the same thing in the eyes of the law) :)
"Depraved indifference to human life" is murder. Putting poison in something you know someone will probably drink, even if you tell them not to, is depraved indifference to human life. Murder. You should go out of your way to not kill people -- this is the opposite.
Like I said, if the death penalty is the punishment for drinking alcohol, fine. But the death penalty doesn't mean you can just murder people. There is a procedure to follow -- a trial, evidence proving the case beyond a reasonable doubt, appeals, etc. You can't just kill someone that committed a crime; you have to prove it first. The government needs to be held to a higher standard than the average man, and if the average man did this, he would be in prison for murder. What the government did, in this case, is inexcusable state-sponsored mass murder.
(Thought experiment: you have a party, and have a punch bowl sitting out. Next to it is a small sign that says: "Poison: do not drink." A few guests drink it anyway, and by the end of the night you have a stack of five dead bodies. Do you really think that you won't be convicted of five counts of murder? A disclaimer doesn't mean you can try to kill people!)