A man with a “violent disposition” has been found guilty of murdering his partner’s baby son.

Kane Mitchell, 31, subjected Teddie Mitchell to a “violent assault” at the flat where he lived with the child’s mother, Lucci Smith, in St Neots in Cambridgeshire, Karim Khalil QC said, when opening the prosecution case.

Mitchell is not Teddie’s father but was cohabiting with 29-year-old Smith, who had children from a previous relationship, the trial at Cambridge Crown Court was told.

Mr Khalil said that on November 1 2019 Teddie “received fatal injuries as a result of being gripped hard, shaken vigorously and having his head struck against a hard surface”.

“In the course of that he suffered rib fractures, fractures to his collar bone and a fractured skull,” he said.

“The forces involved gave him serious brain injuries from which he died.”

Teddie died in hospital on November 11 2019, aged 12 weeks old.

Ely Standard: Baby Teddy Mitchell died in hospital from his injuries.Baby Teddy Mitchell died in hospital from his injuries. (Image: CAMBS POLICE)

Jurors convicted Mitchell of murder on Thursday, following a trial that spanned a month and a half.

He was also found guilty of causing or allowing serious harm to a child.

Mr Khalil said that Smith left Teddie alone with Mitchell for around a quarter of an hour when she went on the school run on the morning of November 1.

She later told police that when she returned home at around 9am Teddie was not taking his milk, Mr Khalil said.

He said that Smith failed to act “once it was obvious that Teddie was very seriously ill”.

Jurors found her guilty of cruelty to a child, for not calling an ambulance sooner.

Smith had made a series of calls to her local surgery and said Teddie made a “high-pitched squeal when he moved” when she took him from his cot, Mr Khalil said.

Ely Standard: Lucci Smith failed to act to help baby Teddy.Lucci Smith failed to act to help baby Teddy. (Image: CAMBS POLICE)

Smith was asked to bring Teddie into the surgery and was expected to arrive by 2pm, but said she could not take Teddie in until she had done the afternoon school run, he said.

She was urged to “call an ambulance immediately” in a call at around 2.30pm, Mr Khalil said, but Smith did not dial 999 until just after 3pm.

Smith was cleared of causing or allowing the death of a child, and of causing or allowing serious harm to a child.

The two defendants are due to be sentenced on February 5.