The farmer? Listen to the evidence and make a decision based on that, which is all I’ve done since reading the anecdotal account.
If he’s told the police he’s going to shoot them if the return, then that shows premeditation.
If they’ve burgled him 17 times, then that has to be factored into the verdict and diminished responsibility will need to be considered.
The fact they’ve visited 16 previous times and he hasn’t been killed suggests that the burglars’ MO doesn’t include violence.
Based on this evidence and this alone, it seems to be manslaughter on grounds of diminished responsibility or murder.
For our mutual Mexican acquaintance, this doesn’t mean that you can‘t defend your property, it just means it has to be a proportionate response to what is happening, just like the law states.