The unidentified juvenile has been charged with five counts of murder, two counts of arson and one count of aggravated arson, Woodford County State's Attorney Greg Minger told the Peoria Journal Star.
The April 6 fire near Goodfield, southeast of Peoria, killed Kathryn Murray, 69; Jason Wall, 34; Rose Alwood, 2; Daemeon Wall, 2; and Ariel Wall, 1.
The fire began at around 11 p.m. on a Saturday night, the paper reported. By the time firefighters arrived a few minutes later, the trailer was engulfed in flames.
Autopsies revealed they all died of smoke inhalation, the paper reported.
Katrina Alwood, 27, and her juvenile son survived.
She and Jason Wall were engaged to be married, the paper reported.
They were the parents of Ariel and Daemeon. Rose was a niece. Muray was Katrina Alwood’s grandmother.
Minger said he decided to charge the boy after reading through various authoritative reports about the fire numerous times, the Journal Star reported.
“It was a heavy decision,” he said. “It’s a tragedy, but at the end of the day it’s charging a very young person with one of the most serious crimes we have.
“But, I just think it needs to be done at this point, for finality.”
Minger said the boy will be subject to a bench trial, before a judge and without a jury.
The child would face five years' probation if convicted and any probationary period would not go beyond the age of 21.
Imprisonment is not an option.
“Probation, given the age, is about the only outcome that could happen here,” the prosecutor told the paper.