Last mass-shooting in New Zealand had it all: numerology, problem, solution. Happened on 11/13/90, 13 people were killed.
"After the shootings, sweeping changes were made to New Zealand's firearms legislation in 1992, including 10 year photographic licences and tight restrictions on military style semi-automatic firearms."
wikipedia.org/wiki/Aramoana_massacre
"Several explosions and huge flames shook Bethel Island on Thursday night, incinerating as many as three homes before firefighters rushed to the scene and began to fight the inferno.
Twenty-foot flames were coming out of three homes next to a levee on the 2700 block of Taylor Road, according to a 5:50 p.m. tweet by the East Contra Costa County Fire Protection District."
sfgate.com/bayarea/article/Explosions-fires-light-up-Bethel-Island-homes-13690241.php
I'll bet every one of his movements was being watched and recorded.