The boy is not being charged because of his age.
The authorities said the boy was under 10 years old and would not be charged.
The boys charged in the killing had no following, the police say, and few friends.
Another boy was charged with child pornography in a similar case.
The five boys were charged with sexual abuse in that case.
Family members say the boy charged in the shooting is known as Andrew.
A 15-year-old boy was charged in the attack, and the police were questioning a second suspect last night.
Five teenage boys were later arrested and charged with murder.
The other boy may be charged with criminal trespass, he said.
The 11- and 12-year-old boys were charged with juvenile offenses.