A 9-year-old child has been charged with five counts of first-degree murder after he allegedly caused a mobile home fire which killed five people, including three children, in central Illinois.

The incident happened on April 6, 2019, killing a 1-year-old, two 2-year-olds, a 34-year-old man and a 69-year-old woman at Timberline Mobile Home Park, Goodfield, 150 miles off the southwest of Chicago.

State prosecutors charged the juvenile with two counts of arson and one count of aggravated arson for intentionally setting the April fire, the Woodford County State’s Attorney Office remarked to local news outlets.

Woodford County State's Attorney Greg Minger wouldn’t disclose whether the suspect was potentially related to the victims, U.S. News reported. However, they said the fire was set with the knowledge that there were people at home.

"It was a heavy decision. 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," Minger told the Journal Star.

Minger said he consulted multiple reports on the fire before going ahead with the prosecution.

According to the AP, USATODAY and Northeastern University mass murder database, this child is the youngest offender in the history of mass killing since 2006.

Gus Kostopoulos, a former prosecutor-turned-juvenile defense lawyer in Chicago said that the prosecutors will face a major challenge while trying to prove the 9-year-old had set the fire with intent to murder, which is customary in first-degree murder cases.

"Nine-year-olds don't know that Santa Claus doesn't exist. They don't know people die and don't come back to life, I don't know if 9-year-olds can form intent to commit murder," Kostopoulos said.

Betsy Clark, the president of Juvenile Justice Initiative and also a leading advocate for children, based in Evanston, Illinois, condemned the criminal justice system’s decision to charge such a young child with murder.

"The charges are completely out of line, given everything we have learned ... especially about the brain development of children," Clark told U.S. News. She also emphasized 14 is the minimum age of criminal responsibility in many countries, including Germany.