Security personnel perform yard-to-yard searches during a manhunt in Sunnyvale
Security personnel perform yard-to-yard searches during a manhunt in Sunnyvale, California, October 5, 2011. A disgruntled worker opened fire on Wednesday at a Northern California cement plant and quarry, killing two people and injuring six, police said. Reuters

Shareef Allman, who killed three of his colleagues and injured six others at a California limestone quarry, died during a confrontation with three sheriff's deputies of Santa Clara County. His autopsy revealed he died of a self-inflicted shot on head.

As a suspect, Allman had become a threat to the public since Oct. 5, the day he eluded law enforcement. His death ends the threat. However, why did he resort to violence and why did he shoot himself at last, baffled people are wondering.

Allman's friends and neighbors know him as a peacemaker, a churchgoing man and a devoted father. His longtime friend Pastor Jeff Moore said Allman would go to clubs when he was young and he was never violent those days. Moore stressed he never saw an emotionally explosive streak in Allman.

However, clues could be found in the foreword of Allman’s book, a self-published novel that describes how he turned his troubled life around.

I had a very disheartened childhood. I felt unloved and hurt, and that hurt feeling turned into hate. Hate for the drugs that my mother used and hate for my father for the women he used and abused.

His friends believed he had conquered that pain with his love for his children and for God. They did never thought Allman would hurt others even though he had complained about being treated unfairly by his managers.

A neighbor of Allman provided the clue. Allman had recently been assigned the shift 10 p.m.-to-6 a.m. at the quarry, which made him unhappy, because it left him less time with his daughter.

My kids, I know, are a gift from above, Allman wrote in his book.

What do you think about the case? Leave your comment below.