Officers were called on March 18 in connection to the crime after the boy was brought to J.W. Ruby Memorial Hospital in Morgantown.
Medics found that Keaton had irreversible head trauma in addition to bruises and cuts on his genitals.
He died due to his wounds only a couple of days later.
The family members say that Keaton did all of this to himself, according to the Daily Mail.
Doctors found the child with a 4cm cut to his penis, as well as testicle and thigh wounds.
According to Harrison Assistant Prosecutor Gina Snuffer, the boy was also bleeding from his brain and eyes, had bruises around his neck and collarbone as well damage to his ears.
Prosecutors have said that Keaton was tortured for months after the passing of his father Christopher, who died of a drug overdose in the summer of 2019.
His mother, Jessica Bishop-Holt reportedly lost custody of Keaton due to drug addiction.
The three accused could face life behind bars if convicted.
Their trials are due on March 1, March 29, and April 19.
