Police in Boston shot and killed a terror suspect outside a drugstore Tuesday after he jumped at them with a large, military-style knife.
Boston police and the FBI said the suspect was under 24-hour-a-day surveillance, but they have not specified why he was being watched.
Police have not identified the suspect, but The Boston Globe newspaper and the Council on American-Islamic Relations said he was Usaama Rahim.
Police said officers did not have their guns drawn when they approached Rahim to question him and opened fire only after doing everything they could to get him to drop the knife.
A police official said the officers considered him to be armed and dangerous. The FBI said an investigation was under way to determine whether the shooting was justified.