Brett Knight murder his former friend Ross Reisner after blindly firing shots - what makes someone snap?

James Wray

Brett Knight had been friendly with Ross Reisner and his partner Kevin Murray for years. He'd even rented a room from them.

However, things did not pan out and they evicted him and he thought they'd also tried to get him blacklisted with local employers.

But what makes some go from having a big fallout with some friends to snapping and grabbing a gun?