Dec. 15 (UPI) -- Anxiety has increased in Providence, R.I., as a person who shot and killed two people and injured nine on the Brown University campus is still at large, though there are "no credible threats," Mayor Brett Smiley said.
A person of interest who was detained by police for questioning was released Monday morning. Smiley said he couldn't rule out that the person had something to do with the shooting.
Smiley told Good Morning America that after processing evidence, "it was determined that this person of interest needed to be released."
"Until such time as we have an individual in custody who we're confident is responsible that we're prepared to press charges and then prosecute, we're going to continue to leave all doors open until such time is that we're in a place where we feel confident that we've got the right person," Smiley told NBC News.
He said there is an enhanced police presence on campus and in the city.
