A teenager has been handed an indefinite sentence after shaking his partner’s baby to death, causing “catastrophic” brain injuries, when he was 16 years old.

Carl Alesbrook, now aged 19, caused whiplash-type injuries, bleeding on the brain, and multiple bone fractures to four-month-old Elijah Shemwell seven weeks after meeting his mother in November 2021.

The defendant, previously of Upper Greenhill Gardens, Matlock, in Derbyshire, denied murdering Elijah but was unanimously convicted after a five-week trial in July.

He was given a minimum term of 14 years, minus the time he has already served, at Derby Crown Court on Friday.

A jury was told that Elijah suffered brain damage from being shaken, including incidents on New Year’s Day and January 2 2022, and had bruises around his body consistent with grip marks.

During the trial, Alesbrook denied being “unduly angered or irritated” by the baby but the court was told he sent a Snapchat message to the baby’s mother, India Shemwell, calling Elijah a “c***” days before he was rushed to hospital.

He also denied that a toothache caused him to “lose his temper” or that he was “jealous” of Shemwell’s relationship with the baby’s father.

Mark Heywood KC, defending Alesbrook, said the defendant was “very young and very immature” at the time of the offences, but was “capable of being a very caring father figure”.

The court heard that Alesbrook looked after Elijah when his mother was away from her home in Acorn Drive, Belper, Derbyshire.

Shemwell, who was 21 at the time but is now 24, admitted two counts of child cruelty in December last year, including the fact she did not dial emergency services more quickly after Elijah became unwell.

She was sentenced at the same court on Friday to three years in prison.

The jury had been shown a video taken by Shemwell of Elijah unresponsive with a floppy arm on January 1, which she sent to friends on Facebook to ask for advice.

Another video shows her son “gasping for breath” before she phoned emergency services on the evening of January 2 and he was taken by an ambulance to Queen’s Medical Centre in Nottingham.

Elijah died three days later on January 5 with fatal head injuries that were described in court as “catastrophic”.

Shemwell cried in the dock as the videos of Elijah appearing “lifeless” were played to the court during the sentencing hearing.

She was described during her ex-partner’s trial as “a thoroughly inadequate mother” who generally and specifically neglected to seek prompt medical attention for her son.

Prosecutor Vanessa Marshall KC said Shemwell “failed to prioritise the needs of Elijah over her own” and should have known Elijah was “testing Mr Alesbrook’s patience”.

She knows she has let down her son, she knows she has let herself down and she has let down her family

She said: “It is the prosecution’s case that she should have appreciated shortly after he had been shaken, for probably the second time, that Elijah was very unwell and needed medical attention.

“That is particularly the case when she would have seen, as we have, fresh bruising on Elijah’s face.”

Shemwell’s defence lawyer Darron Whitehead said: “She knows she has let down her son, she knows she has let herself down, and she has let down her family.

“It is her inactivity, it’s her failings, that will haunt her for the rest of her life. She misses Elijah and no matter what is said in this room, or in writing, she loved her son.”

A victim impact statement by Shemwell’s mother, Rachel Shemwell, read to the court by Ms Marshall, said her daughter was “not the best of mums” and things could have “turned out differently” if she had asked for help.

She wrote: “We will never get Elijah back and can only remember the happiness he brought us in his short life.”

Mr Justice Jeremy Baker said: “The effect of Eli’s death on those who loved him is evident. Nothing this court can do will assuage their overwhelming sense of loss.”

The judge told Alesbrook: “There is only one sentence that can be imposed and that is detention at His Majesty’s Pleasure.”

Detective Chief Inspector Greg McGill, who led the investigation into Elijah’s death, said: “While a child himself, even a teenager knows the fatal risks posed by shaking a four-month-old baby boy.

“The force used to squeeze his tiny body broke his ribs – while the shaking caused such significant damage that his brain became starved of oxygen leading to his death.

“While India was quite simply an appalling mother, she could never have foreseen the brutal actions of Alesbrook.

“However, it is quite clear that she could and should have taken far better care of Elijah and she will have to live with the consequences of both her action and inaction for the rest of her life.”