Greenock-born entrepreneur, who runs firms in the financial sector and restaurants in California, said: “As far as I’m concerned, the guys who killed Adrian also killed Cannon. They took both my sons.“Cannon was a bright boy with natural intelligence and forward thinking.“But he couldn’t get his head around how his brother died and it took him to a really dark place.“He was verbal about how he felt and said he couldn’t deal with the fact Adrian was no longer here.