The youngster died from abdominal injuries on June 5, 2018, after his ribcage was "crushed" at a flat in West Bromwich where his mother and her partner lived.
Nathaniel Pope was found guilty of his murder and sentenced to life with a minimum of 24 years, whilst his partner, Kemarni's mother Alicia Watson, was found guilty of causing or allowing the death of her son and other child cruelty charges, and sentenced to 11 years in prison.
A serious case review into the toddler's death was commissioned by the Sandwell Safeguarding Children Board before the lengthy trial at Birmingham Crown Court, and has now been released.
And the independent review has concluded there were "no missed opportunities for professionals to intervene and prevent the death" of the youngster.
And Lesley Hagger, chair of the Sandwell Children's Safeguarding Partnership, has concluded there were "no missed opportunities for professionals to intervene and prevent his death".
She said: "Our thoughts and sympathies are with all those who knew and loved Kemarni. Partners in Sandwell always look at what we can learn from sad cases like this and where we can identify areas for learning and improvement.
"The review did provide some learning from this case and I can confirm this has already been shared with professionals and implemented by agencies.
“This learning was around training for agencies regarding the thresholds for Early Help for families, promotion of funded nursery provision and childcare, and the need to better reflect the ‘voice of the child’ in records.
“As partners, we are fully committed to doing everything we can to protect children. Kemarni and family members did have contact with a number of services across the partnership. Kemarni himself had contact with ‘universal services’ – being those services we would expect any young child to have contact with.
"The independent review has concluded that there were no missed opportunities for professionals to intervene and prevent his death. There were no identified safeguarding concerns regarding Kemarni prior to his death in 2018, and there was no children’s social care involvement directly with him."
The report said the West Bromwich flat was described as being "cluttered" by professionals but the state of it did not cause concern to the midwives or health visitors.
It said the youngster was "always taken" for appointments with health professionals with one health visitor noting some concerns about his speech development, but described him as a "happy little boy who was very sociable".
Shortly after Kemarni's birth, he and his mother were visited by a health visitor with Watson later attending a baby clinic – and the pair attended them "on a regular basis" when the youngster was three months old.
He was taken to the GP on two occasions suffering from nappy rash and a cough and was described by the professional as a "lovely, plump and happy baby" – and was found to be progressing normally up to five months old.
The youngster was, however, admitted to hospital overnight for observations having attended both the GP and emergency department with a respiratory infection, the review said.
A health visitor, who undertook the child's nine to 12 month development review, found the youngster had "mostly normal development" and had given Watson strategies to increase his confidence in walking and reduce his reliance on the baby walker.
Kemarni received all immunisations in the prescribed times and progressed normally. And then in 2016 he was taken to the emergency department suffering from a minor head injury – and was taken to the GP suffering from sickness and diarrhoea. Nothing significant arose from those two visits.
A year later and during the two-year developmental review, it was noted the youngster was not reaching some expected areas of development and had some speech and language difficulties with a follow-up appointment agreed.
But over the next two months Watson and her son began to miss appointments and did not present themselves for the development check with no explanation given. The mother did take him in for a check later on where he was found to be progressing well.
In March the following year, Kemarni's place at nursery was terminated due to funding issues as Watson sought alternative funding – meaning there was no nursery provision for him during this period.
On the day the youngster died, Watson had taken him to an urgent care walk-in centre with a history of vomiting on and off for five days and he was seen by the specialist nurse practitioner.
It is recorded that on examination he was alert and aware and there were "no red flag issues" but he was diagnosed with viral gastroenteritis and was prescribed with dioralyte sachets.
Kemarni was left in the care of Pope afterwards and when Watson returned to her home, she found the youngster in an unresponsive state and an ambulance was called, the review said.
The review recommended the Local Safeguarding Children Boards (LSCB) should review training provided to agencies regarding the thresholds for Early Help and ensure agencies are aware of their responsibilities to apply thresholds correctly.
Sandwell Council should be asked by the LSCB to give assurance that funded nursery provision/childcare is promoted and take up encouraged, particularly within families with children who are vulnerable, the report said.
And agencies should be reminded by the LSCB of the need to include the "voice of the child" when recording information.
The review comes after it was revealed the jail sentences of the couple are set to be reviewed by the Court of Appeal for being "too lenient".
Convicted drug-dealer Pope, 32, of Evans Road in Wolverhampton, was found guilty by a jury in April following a lengthy trial which heard Kemarni had 34 separate areas of external injuries.
The boy's ribs had been fractured 19 times over a period of four weeks with the force akin to being thrown off a building.
Watson, 31, of Radnor Road in Handsworth, was frequently erratic in the dock and witness box, crying, swearing and refusing to answer questions about the death of her boy at her West Bromwich flat in June 2018.
The couple, who blamed each other from the witness box, continued to live together for several months after Kemarni died.