HAMBURG—The migrant who killed one person and injured six others in a knife attack in a Hamburg supermarket was a radicalized Islamist known to German security agencies, but also believed to have psychological problems.
Officials said on Saturday the agencies had believed he posed no immediate threat.
A security lapse in a second deadly militant attack in less than a year, and two months before the general election, would be highly embarrassing for German intelligence, especially since security is a main theme in the Sept. 24 vote.
