James Howson, 25, of Nelson Road, Doncaster, was given a life sentence at Leeds Crown Court yesterday for the murder of 16-month-old Amy Howson. The judge imposed a 22-year minimum term, saying he committed a "chilling and brutal attack".

Adrian Waterman QC, defending, told the court that when Howson was expelled from school aged 14, a worried teacher noted in a report: "This boy will commit a murder before too long. I have never seen a such a disturbed young man."

The court also heard that as a child, he often subjected girls to violent, unprovoked attacks. He also had a track record of physically abusing women as he got older, yet had no previous convictions.

Sentencing Howson, judge, Mrs Justice Cox, said: "Exactly what happened that caused you to do what you did on that night remains unclear.

"At some point, probably because she was in pain or distress you placed Amy on your knee and then deliberately pushed her down on some object or on you knee, fracturing her spine.

"The bone was completely dislocated, resulting in spinal shock, rapid unconsciousness – mercifully – and then death."

The final brutal act followed two months of sustained physical abuse by Howson on the defenceless baby. He had punched and slapped the baby as well as pulling and twisting her limbs, causing six fractures to her arms and legs.

The baby also had a fractured rib and a serious head injury which led to bleeding of the brain and contributed to her death. She was also dehydrated and malnourished, weighing the same at her death as she had at six months old.

Amy's mother Tina Hunt, 26, escaped jail and was given a 12-month suspended sentence after admitting child cruelty. She admitted the charge on the basis that she did nothing to alert the authorities to her daughter's plight and did not seek medical attention for her daughter even after realising that she was in distress.

The judge said Hunt was in a violent and controlling relationship, and was unable to tell anyone what was going on. Howson had even set up a closed circuit TV camera in order to prevent health visitors coming to check on Amy.

The judge told Hunt: "Your level of culpability falls at the lowest end of the scale", after hearing how Howson completely dominated her and was often violent.

She also said Hunt was in the lowest one per cent band of intelligence.

At one point during the legal process, prosecutors tried to pursue a murder charge against Hunt, but it was rejected.

In emotional scenes in the courtroom, Howson's mother, Jane Wilkinson, collapsed as the judge passed sentence. Outside the court, members of his family vociferously protested the ruling, saying that Hunt should also have been imprisoned.

Howson showed no emotion as he was led from the dock.

The judge said to him: "I have not seen the slightest evidence of remorse from you for what you did."

Det Supt Carl Sturgess, who led the investigation, said: "This has been a most wicked and evil murder of an innocent child.

"The catalogue of horrific injuries have been some of the worst I have seen in 30 years of policing.

"The two very people who should have been providing love and protection for this child brought her nothing but misery."

The officer said that, although Hunt had a low intelligence and appeared to be scared of Howson, she should have acted.

Outside court, Amy's grandfather, Colin Hunt, said: "Tina was manipulated mentally and psychologically by James. She couldn't even tell me what was going on.

"Life should mean life but what can you say. Twenty-two years is all right but it won't bring Amy back."

A spokeswoman for the Doncaster Safeguarding Children Board said an investigation would be launched into Amy's death.

The spokeswoman said: "The death of Amy and the abuse she suffered was horrendous and the parents have rightly been brought to justice."