"I am not asking that you like this man and his somewhat useless life to date; alcohol, drugs, and probably sponging off the taxpayer appears to have ruled his life and probably others in the house."
Mr Chambers dismissed the prosecution's assessment of Loffley, saying their case failed to prove guilt beyond reasonable doubt.
Someone else was responsible for the fatal injuries inflicted on JJ, said Mr Chambers.
"Someone entered JJ's room, damaged JJ, removed JJ's clothing, and for whatever reason, then left the room. You can't discount the possibility that something like that occurred."
Crown prosecutor Phil Hamlin also asked the jury to assess the evidence and Loffley's character, saying Loffley had a history of lying and distancing himself from injuries associated with JJ.
The accused's evidence had revealed inconsistencies and shown him to be a liar, said Mr Hamlin.
"We can see there's a theme coming through that suggests Mr Loffley is distancing himself from any domestic violence to the child, any domestic violence to the mother."
On the day JJ died, Loffley delivered a fatal blow to the child when he "angrily and violently deals to him", said Mr Hamlin.
Loffley insisted on putting JJ to bed that day because he didn't want Ms Lawrence to see JJ's injuries, he told the jury.
When the ambulance arrived the child was cold and "had been dead for some time".
Mr Hamlin dismissed the suggestion JJ's mother, Josephine Lawrence, was involved in the toddler's death, and said her guilt referred only to her inability to protect her child from harm.
"That's the anguish that Josie Lawrence talks about and she accepts that blame, but she is not to blame for causing the death of her son."
On the day JJ died, Loffley had cuddles with the two-year-old and played with him in bed, Loffley told police.
"I wasn't rough with JJ," he said.
During a two-hour police interview, Loffley admitted to having hit children and women.
The judge will sum up the case tomorrow.
