The law describes behaviors/actions/stuffs that are or are not crime. Murder is defined as the unjustified killing of a human. (Usually.) there are then variations of “murder”.
Manslaughter is the unlawful killing of a human being without malice.
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B. Involuntary manslaughter consists of manslaughter committed in the commission of an unlawful act not amounting to felony, or in the commission of a lawful act which might produce death in an unlawful manner or without due caution and circumspection.
So any behavior that fits that is, by definition invol. Manslaughter.
I’ve added emphasis to the relevant bit here. Let’s break it down.
Baldwin was preparing to shoot a sequence of a western movie. This is a lawful act.
he was handling a firearm. This might produce death.
he was handling the weapon in an unsafe manner; that is, without due caution.
these things resulted in Alina dying.
This also gets into presumption of innocence. It’s a procedural presumption. It’s a very important procedural stipulation meant to protect the civil liberties of the accused. (It’s violated on a regular basis but that’s a different matter.)
Regardless, the crime happened. If you’re guilty of a thing, you are guilty regardless of if you are caught, or discovered, or accused or even indicted or they blame some one else. None of that changed that you did that thing and are guilty. The trial doesn’t magically guilty- you are found to be guilty.
Like how fossils are found. They’re always there. Just because we don’t know that they’re there, doesn’t mean they don’t exist. The fact of their existence is immaterial to any one’s knowledge of that fact.
Similarly, the fact of one’s guilt is immaterial to anyone’s knowledge of that fact. (For example, a drunk driver so heavily inebriated they don’t realize they ran some one over. Or hunters plinking in the woods unaware that kids were playing behind their targets.)
The court procedural rules say he is presumed to be guilty until the fact of his guilt is found in a court of law.
He committed actions which are defined as being involuntary manslaughter.
He doesn’t get to say he was behaving with due care because there was an inexperienced, inept armorer, somewhere around there. That’s not how it works.
From an occupational accident perspective, it doesn’t matter that there was a “safety coordinator”, it’s still unreasonable behavior that lead to Alina dying, as an employee (and employer, but that’s a different set of charged ) he has an obligation and duty of care to maintain a safe working environment- and to report unsafe environments.