A single mother apparently slit the throats of her three children, then sat with them and her toddler in their burning home until she died from smoke inhalation last week, according to police and autopsy results released Thursday.

Police had said the case appeared to be a murder-suicide, but it wasn't clear until Thursday who killed the family members inside their Staten Island home.

The fire was briefly believed to be accidental before it became a homicide investigation.

One of the children who died, a 14-year-old boy named C.J., had been found with a razor under his body and had a history of starting fires. But the medical examiner's office on Thursday ruled the boy's death a homicide and said mother Leisa James' death was a suicide, clearing up remaining questions on who was responsible. The deaths of the other three children also were ruled homicides.

It still wasn't clear how the July 22 fire was started, but fire investigators say it was deliberately set.

Firefighters found the charred bodies of Jones and her two daughters, 7-year-old Melonie and 10-year-old Brittney, in a front room. C.J. was found slumped over a bed in a back bedroom. Police said later that day that the throats of the two girls and C.J. had been slashed.

Jones' 2-year-old son, Jermaine, was pulled out alive but died at a hospital of smoke inhalation. His throat was not cut.

Given the razor under C.J.'s body and his history of playing with fire, it was theorized that he might have killed his family, set the blaze and cut his own throat.

But an initial round of autopsies found that Jones and C.J. both had ingested some type of drug, according to two law enforcement officials who spoke on condition of anonymity because they were not authorized to give out medical information.

Also, a badly damaged note with the words "am sorry" was found in an another room, and investigators concluded it was written by Jones. It remained unclear whether it was a suicide note, but that discovery — combined with the initial drug evidence — led to suspicions she killed her children.

The pills didn't contribute to their deaths. C.J. died from his neck wound, said Ellen Borakove, spokeswoman for the city medical examiner's office.


Associated Press writer Tom Hays contributed to this report.