PROVIDENCE, Rhode Island — Authorities on Monday had renewed a manhunt for the gunman who killed two students and injured seven more at Brown University over the weekend, after releasing a man who had been held on Sunday as a "person of interest" in the shooting. Though officials said late on Sunday they were resuming the search for a suspect, they said there were no credible threats to the community and that they would not reimpose a shelter-in-place order for the campus and the surrounding area that had been lifted earlier. Police have released surveillance footage showing the possible shooter dressed in black walking near the building where the attack took place, though his face is not visible. The gunman fled after shooting students in a classroom in Brown's Barus & Holley engineering and physics building, where outer doors had been left unlocked while exams were taking place, according to police. At a press conference late on Sunday, officials said there had been enough evidence to justify taking into custody the unnamed person of interest, a man in his 20s. But Providence Mayor Br