It’s been a year and a half since a deadly mass shooting in San Bernardino, California. The two attackers were killed after they gunned down 14 people . Georgia native Shannon Johnson , a graduate of Macon’s Windsor Academy, was one of them. He died shielding a co-worker in the attack . Friends of the family say Johnson’s heroics were also in his DNA . His father died years earlier trying to save a co-worker during a factory accident. We talked with Shannon’s brother, Rob, about the family’s