After reading a bit about it... I've taken the following view...
1) Alec Baldwin, the actor, practicing for a scene, should not be charged with a crime. On a movie shoot, with an armorer, I don't think it is unreasonable for an actor to presume that the props that they are using are safe. In his capacity as an actor - I'd have a hard time finding fault with Baldwin (no matter how much of a giant douche-bag he is).
2) Alec Baldwin, the executive producer, the person ultimately responsible for the operation including safety related concerns, may very well have been grossly negligent in his actions, in a manner that led to the death of a member of his team. In THAT capacity, as the person ultimately responsible for the safety of the working environment, it may make sense to charge him criminally - and I have zero doubt that once the criminal trial is over the family of the dead lady will sue him civilly. It sounds like he'll have a very hard time proving that he hired the best of the best armorers, or that they had industry leading (or even standard) safety measures in place.
If I were an actor - and were using guns - I'd be damn sure to clear them before I did anything... but I'm a "gun guy" who shoots guns and treats every gun like it's loaded... I actually think that were I an actor I'd have a REALLY hard time pointing a gun at someone and pulling the trigger... it's just so engrained. But from a LEGAL perspective - I have a hard time making everyone on the set responsible for clearing guns. The armorer is there for that exclusive purpose... and the executive producer(s) are responsible for ensuring that there is appropriate policy, protocol, and that competent safety personnel are in place. He failed in that...
My 2 cents...