Two people have been killed in stabbing attacks at a home and a shopping centre in Massachusetts before an off-duty police officer shot and killed the suspect.
Bristol County prosecutor Thomas M Quinn III said Arthur DaRosa, 28, of Taunton, crashed a car outside a home in the city, 40 miles south of Boston, walked inside and stabbed two women, one of them aged 80. The 80-year-old was taken to hospital, where she died. The other woman is being treated for life-threatening injuries.
DaRosa then drove to the Silver City Galleria mall and crashed a car through the front of a Macy's store, Mr Quinn said.
He assaulted multiple people inside the store before running to a restaurant and stabbing two people, including a 56-year-old man who later died. An off-duty deputy sheriff intervened at the restaurant and shot DaRosa dead, Mr Quinn said.
A motive for the attacks remains under investigation, but state police said they have found no evidence of a connection to terrorism.
"There is no continuing threat to the public," said Dave Procopio, a state police spokesman.
Justin Pizarro, 19, told the Boston Globe he was working at a store in the mall at the time of the stabbings. He told the newspaper that a security guard told him to close the gate of his store.
Mr Pizarro said he was "shaken up", but that "the security guards handled it pretty well".