Two-year-old Keanu Williams, who was beaten to death by his mother, had 37 separate injuries, including extensive bruising to his head, stomach, back and legs, when he died.
The toddler also had a fractured skull and a fist-sized tear on his stomach when he was found dead in January 2011.
The detective in charge of the investigation said it was the "worst" child abuse case she had ever seen.
More top news
Mother of Bobby and Christi Shepherd says Thomas Cook apology was 'too little too late' as she calls for greater safety standards.
The Neverland ranch where pop star Michael Jackson lived until running into financial difficulties has been put up for sale.
A 43rd generation direct descendant of the Prophet Muhammad, the Prince has vowed to clean up Fifa's act.