The family of a 10-year-old boy who was allegedly killed over the weekend by another 10-year-old rallied Friday in downtown Sacramento to get justice for their loved one. Keith Jhay “KJ” Frierson, 10, was gunned down at a Foothill Farms townhouse complex on Saturday. His family said they were told by the Sacramento County District Attorney’s Office that the accused child, who has not been publicly identified, would not face charges in KJ’s death. The D.A.’s Office said the boy’s father is the only one criminally responsible for KJ’s death. Arkete Turan Davis, 53, charged in Sacramento Superior…