Authorities are trying to determine why a man went on a stabbing rampage in Massachusetts, killing two people and assaulting and stabbing more in a house and a shopping mall before being shot dead.

The suspect in Tuesday's attacks has been identified as 28-year-old Arthur DaRosa.

Authorities say it all began when DaRosa crashed a car outside of a house in the city. They say he walked inside the home and stabbed two women, including an 80-year-old who later died.

Authorities say DaRosa then drove to the Silver City Galleria mall, where he crashed into the front of Macy's department store. They say he assaulted multiple people inside the store before running to Bertucci's restaurant and stabbing two more people, including a 56-year-old man who died at a hospital.

An off-duty sheriff's deputy then fatally shot DaRosa.