He was living in a house his brother had owned. He had no legal right to the house, and when his brother died he was served with eviction papers.
Apparently, the guy was a nut who was well known to police. He was one of those people who declare themselves a "sovereign entity" not subject to the normal laws everybody else has to abide by.
So, when the cops came to evict him, he shot at them. And the inevitable result ensued. He was well ventilated by the police.