The mother had the greatest responsibility.She was in the home and actually witnessed the abuse.
We don't know that anyone else saw the bruises which would be easily covered with a shirt,or in regard to facial bruises explained away or the child hidden until healed.
Were the neighbors close enough to the child to see the bruises?
Anyone could have expressed a concern,but was there enough evidence at the time for them to go to the authorities with any concerns of abuse?
Sadly many children live with the conditions of drugs and abuse and little is done.
IMO
But the mother wasn't the person raising this child according to some information. Someone who had the care and custody of Carnel until a month prior to his murder made the decision to turn Carnel back over to his drug addicted mother and her felon addict live in lover rather than trying to get legal custody.
It doesn't appear that it would have been a difficult fight in family court. Why didn't it happen? Instead this child was taken from an apparently safe environment and turned over to the care and custody of his mother a month before his death, when it was no secret that the mother and her felon lover had some very serious addiction problems, in addition to AB's criminal problems.
That was no secret to anyone.