A "vigilant" and "brave" Vallejo citizen who happens to be a trained mixed martial artist detained a man police say deliberately started a brush fire Saturday before officers arrived and arrested him. Alex Bello said his natural instincts kicked in when he saw a man use a flare to ignite the blaze behind his Vallejo apartment complex. "It was a personal fire right behind my house, so it was something that needed to be done," Bello said in an exclusive interview Tuesday with NBC Bay Area. Police said the suspect drove to the area near Admiral Callaghan Lane Turner Parkway...