Given the actual nature of the traps, it seems reasonably unlikely that someone would have been killed by them (hence the likely difficulty in charging them with anything too serious).
The use of the term ‘boulder’ is disingenuous in the report, in my opinion: the small rock pictured isn’t what the common concept of a ‘boulder’ would be called - that word is clearly used in order to specifically make people think of something far worse than it really is. I’m not sure it even meets the technical definition of a boulder according to some of the dictionaries I looked up (a rock larger than 25 centimeters in diameter - roughly the size of a men’s basketball) it certainly isn’t what people think of when they hear ‘boulder’ (which is pretty much a rock several feet in diameter). The spikes sticking out of the ground were a more dangerous trap, and given the fishing line intended to trip someone into them, possibly hazardous even if you are aware of their presence.
Not that they couldn’t cause a pretty reasonable amount of damage, but it certainly explains the difficulty in charging them with ‘attempted murder’. Were I to be on a jury where that charge is thrown at them, I would find myself unconvinced. If there’s a charge that covers an attempt to cause serious injury, I can see that sticking, but would find myself hard pressed to believe attempted murder.
Aggravated Assault seems like the appropriate charge.
In Utah, Assault is defined as “an act, committed with unlawful force or violence, that causes bodily injury to another or creates a substantial risk of bodily injury to another” and it’s Aggravated if the person uses a dangerous weapon or “other means or force likely to produce death or serious bodily injury”.
That said, they could have been charged with the lesser crime of Reckless Endangerment: “A person commits reckless endangerment if, under circumstances not amounting to a felony offense, the person recklessly engages in conduct that creates a substantial risk of death or serious bodily injury to another person.”
Only if the jury buys the “We were totally trying to get animals, man” defense. I suspect that the jury will decide that the morons are lying about that.
Why are they mutually exclusive? From my short glance at the quoted statute, it seems that even if they were truly hunting critters, their chosen method could violate both.
If they were truly hunting critters, I think they could be in violation of the “reckless endangerment” clause in addition to attempted violation of hunting and game laws, if the law actually recognizes failed attempts to poach or hunt. But I think that the prosecution will have no trouble convincing a jury that these traps are not involved in hunting animals in any way.