"It's a horrific crime scene," Prosecutor Paula Dow said. "We have multiple victims and a fire that looks like a coverup."
The fire was reported at 7:45 a.m. in a three-story wood frame residence on Columbia Avenue near the Newark-Irvington border.
The fire was extinguished within an hour. The two lower floors of the home were extensively damaged.
Newark Fire Department Director Dave Giordano told The Star-Ledger of Newark that one female in the house had been shot to the head. The cause of death of the other victims was not immediately clear, and it was not clear if the injured person was one of those who had been shot.
Paul Loriquet, spokesman for the Essex County Prosecutor's Office, said the injured person was in the operating room at University Hospital in Newark late Monday morning.
Detectives from the Essex County Prosecutor's Homicide Squad and Arson Task Force along with Irvington police were on the scene.