A police tip led to the arrest of a man who is the main suspect in the beating of a Giants fan on Opening Day at Dodger Stadium. Stow, 42, is being treated there for a traumatic brain injury suffered in the March attack. Los Angeles police raided an East Hollywood apartment building Sunday and arrested Giovanni Ramirez, 31, on suspicion of assault with a deadly weapon. Police are still seeking a second attacker and a woman suspected of driving the pair from the scene.