A teenager who shook his partner’s baby to death when he was 16, causing “catastrophic” brain injuries, has been sentenced to indefinite prison.

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

The defendant, formerly of Upper Greenhill Gardens, Matlock, in Derbyshire, denied killing Elijah but was unanimously convicted following a five-week trial in July.

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

During the trial, Alesbrook denied being “overly angry or upset” with the baby, but the court was told he sent a Snapchat message to the baby’s mother, India Shemwell, calling Elijah a “s***” days before he was taken to hospital. .

He also denied that the 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 crimes but was “capable of being a very caring father figure”.

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

Shemwell, then 21 but now 24, admitted two counts of child cruelty in December last year, including failing to call emergency services more quickly after Elijah fell ill.

The jury was shown a video of Shemwell filming Elijah unresponsive with his flabby arm and sending it to friends on Facebook for advice.

Another video shows her son “gasping for breath” before calling emergency services on the evening of January 2 and being taken by ambulance to Queen’s Medical Center in Nottingham.

Elijah died three days later on January 5 from fatal head trauma, which was described in court as “catastrophic”.

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

During her ex-wife’s trial, she was described as a “totally incompetent mother” who generally and specifically neglected to seek emergency medical attention for her son.

Prosecutor Vanessa Marshall KC said Shemwell “failed to prioritize Elijah’s needs above his own” and should have known Elijah was “testing Mr Alesbrook’s patience”.

“This is especially true when we see the new bruises on Elijah’s face.”

Shemwell’s defense lawyer Darron Whitehead said: “He knows he let his son down, he knows he let himself down and he knows he let his family down.

“It is his inaction and failures that will haunt him for the rest of his life. “He missed Elijah and loved his son no matter what was said in this room or in print.”

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

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

His Honor Judge Jeremy Baker said: “The impact of Eli’s death on those who loved him is clear. “Nothing this court can do can alleviate their overwhelming sense of loss.”

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

“The force exerted to squeeze his little body broke his ribs; the concussion caused such severe damage that his brain was deprived of oxygen, leading to his death.

“Although India was a pretty terrifying mother, she could never have foreseen Alesbrook’s brutal actions.

“But it’s pretty clear that she could and should have taken much 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.”