A man has been jailed for eight years after shaking and killing his partner's child in a fit of temper.
Craig Lewis, 32, had already admitted manslaughter and inflicting grievous bodily harm on 22-month-old Kieron Barley causing him catastrophic brain injuries at the family home in 2011.
Sentencing Lewis today at Birmingham Crown Court, Judge William Davis QC told him: "I am asked to consider you are now remorseful and contrite, but I have difficulty in accepting that proposition.
"Indeed, the report compiled by the very experienced probation officer states 'the defendant's explanation for his conduct was underlying stresses coming to head - in my view Mr Lewis does not fully explain his behaviour for both offences.
"'The trigger appears to have been relatively minor and he reacted with considerable violence towards a young and vulnerable child'."
The toddler's 26-year-old mother Louise Barley, of Denshaw Road in Kings Heath, Birmingham, who had previously admitted child cruelty, was jailed for 15 months at the same hearing.
It emerged during the case Kieron had been admitted to Birmingham Children's Hospital following the first of two incidents at the home, in May 2011.
However doctors there failed to spot compression fractures to two vertebrae in his upper spine.
There was also evidence of bleeds in both of his eyes and bleeding on the brain.
These injuries, inflicted by Lewis in the first of two serious attacks on the boy, were only discovered in a post mortem examination after his death in June, some three weeks later.
Rachael Brand, prosecuting, said Kieron had suffered with developmental delay, was not trying to crawl and could not walk, and doctors had given a tentative diagnosis of cerebral palsy.
Against this background, Lewis had moved in to a shared flat with Barley and the toddler.
On May 28, 2011, Barley went to the shops leaving Lewis alone inside the flat with the little boy to help him to learn to walk.
But Lewis lost patience with the boy and slammed him into the hard floor.
Ms Brand said: "Mr Lewis said he was trying to help Kieron to walk but became frustrated at the lack of progress.
"He said he held Kieron, facing away from him, under his arms and swung him around quickly and slammed him down on the ground with his legs locked underneath.
"His feet impacted hard on the ground, then when he (Lewis) released him, he impacted hard on the floor."
He dialled 999 and on the phone to the call handler lied telling them Kieron had "fallen and banged his head on a wooden part of the sofa", and described the boy as being "really floppy".
Later, at the hospital doctors found "a small abrasion" on the youngster's back, but there was "no tenderness to the scalp, no fractures and observation was recommended".
Against medical advice for further observation, Barley took the child home with Lewis.
She would later lie to police telling officers she had been present during Kieron's damaging fall, in the "genuine belief" Lewis had had nothing to do with the boy's injuries, according to her barrister Kristina Montgomery QC.
Ms Brand said that at home Kieron was vomiting and crying, and was in and out of hospital overnight between May 28 and May 30.
Despite continued health problems, Barley did not tell a health visitor on June 9 about his problems telling her he was "recovering from a vomiting bug".
In the fatal attack, the family had been on a day out on June 19 but when they returned home Kieron wet his nappy.
Ms Brand said: "He (Lewis) took Kieron to the bedroom to change him, while he asked Louise to run a bath.
"Kieron was crying and Lewis lost his temper in the bedroom.
"He shook Kieron causing the child's head to move rapidly back and forth.
"He then threw Kieron into the cot, causing his head to hit the railing, as he landed on the mattress."
Barley, who was not in the room at the time, dialled 999 telling the call handler she did not know what had happened, Ms Brand added.
Kieron was resuscitated and spent several days in the intensive care unit but his life support was removed on June 23.
The toddler's "catastrophic brain damage" was "caused by shaking with, or without, an impact"," Ms Brand said.
A skeletal survey then revealed "the vertebrae fractures, caused on May 28".
Lewis and Barley were first questioned and later arrested by police investigating the toddler's death, before being charged in June 2013.
They had denied the charges against them, and only in February this year changed their pleas to guilty.
Andrew Lockhart QC, in mitigation for Lewis, said his client had cocaine and alcohol problems which he had struggled to deal with.
He said Lewis was "struggling to deal with life".
It was against this background Mr Lockhart added that Lewis twice attacked the little boy, including the incident in June in which there was "a fateful shake, a fateful throw - and it was all over".
Character references stated Lewis was "a good father" until what his barrister described as "these dreadful lapses".
Mr Lockhart asked the judge to give his client credit for his guilty pleas.
Ms Montgomery QC, for Barley, said her client had "poor self-esteem" and had acted out of loyalty to Lewis, in the "genuine belief" he had had nothing to do with the attacks.
She added that it was only shortly before Lewis's admissions earlier this year that Barley found out the truth about what had happened to her little boy.
"She accepts that she did not do everything she could or should have done to alleviate what happened on May 28," said Ms Montgomery.
She added: "She has been punished - she is genuinely remorseful.
"She feels responsibility and guilt, and she will find the remainder of her life difficult."