I agree with your view. The fact that the killer went through the stress of making homemade guns, which likely involved lots of hiccups, shows he had a very dee

I agree with your view. The fact that the killer went through the stress of making homemade guns, which likely involved lots of hiccups, shows he had a very deep grudge for his target, and I see being (allegedly, can't confirm yet) raised in a religious cult that bankrupted your mum as an ideal catalyst for such a grudge. And if recent years have taught me a lesson, it's that real life is often stranger than friction. What you think can only be achieved by state-level, mafia-like collaboration ends up being the work of random individuals (e.g., that Bitfinex hack where two funny characters were caught with $4.5bn of stolen bitcoin).