Jacob Spears described being shot and running to safety as he recovers following the mass shooting that killed two students, Ella Cook and Mukhammad Aziz Umurzokov, and wounded nine at Brown University; authorities released enhanced photos and video and the FBI is offering a $50,000 reward.Spears said the bullet hit his back, two people applied pressure to his wound, paramedics took him into immediate surgery at Rhode Island Hospital, and he now expects to miss travel home for the holidays while he slowly recovers and says he is grateful "to be alive."Investigators released clearer stills and upgraded clips showing a roughly 5-foot-8, stocky person wearing a face covering on Providence's East Side hours before the attack, Rhode Island Attorney General Peter Neronha said authorities hold additional unreleased footage and asked anyone with information to call the FBI tip line or 401-272-3121.