New York (CNN) -- A boy a New York tabloid tabbed a "suicidal teenage pyromaniac" was actually a murder victim, a spokeswoman for the New York City Medical Examiner's office said Thursday.
A house fire killed a mother and four children on Staten Island, New York, last Thursday, the New York Fire Department said.
Ellen Borakove, spokeswoman for the medical examiner, said the ME had determined the mother died of suicide by smoke inhalation, while the 14-year-old in question was a homicide victim, with his throat slit.
Early in the investigation, police had implied they suspected the boy, noting that he had been seen by neighbors setting fires and that was found lying atop a blade believed to have been used to kill his siblings. The "New York Post" called the boy a "teenage pyromaniac."
The mother was in her 30s and the children ranged in age from 2-years-old to 14, the fire department said.
Firefighters responded to the blaze shortly before 4:30 a.m., the fire department said.
The fire apparently began on the second floor of the multi-family house and extended through the roof, fire officials said. The other residents of the home escaped uninjured, they added.
CNN's Megan Miller contributed to this report