Santino William Legan: Gilroy shooter from boxing-loving family, cited 'Might Makes Right' - USA TODAY

Santino William Legan: Gilroy shooter from boxing-loving family, cited 'Might Makes Right'  USA TODAY

Santino William Legan, the 19-year-old named by police as the Gilroy shooter, wasn't a troublemaker -- but apparent Insta posts reveal his anger.