Woodford County coroner Tim Ruestman said the fire was intentional. The local prosecutor, Greg Minger, did not reveal details about the suspect: it is not known if he had any kind of relationship with the victims.
"It was a difficult decision. It's a tragedy, we are accusing a very young person of one of the most serious crimes we have. But I think we have to do it," he said.
A great challenge for prosecutors will be to prove that the boy intended to kill, an essential condition in cases of first-degree murder, said Gus Kostopoulos, the juvenile's defender in Chicago.
"Nine-year-olds don't know that Santa Claus doesn't exist. They don't know that people die and don't come back to life. I don't know if nine-year-olds can intend to commit murder," he said.
In case of being convicted, the child could pass at least five years on probation and up to a maximum of 21. You could undergo special therapy and counseling.