Authorities are again searching for the person seen in grainy video walking away from the Brown University shooting that killed two students and injured nine. Officials said late Sunday that they released a person of interest they had detained earlier in the day, finding no reason to keep him in custody. This setback left law enforcement without a known suspect. The shooting happened Saturday during a busy time on campus, causing chaos and a lockdown. During a news conference Monday, authorities released three new videos that showed a masked man in a dark jacket two hours before the attack. Although the footage didn’t show his face, the video provided the clearest images yet of the suspect.