A delivery driver who murdered his wife, set fire to their home, and blamed their teenage son has been jailed for at least 29 years.

Amidu Koroma, 48, stabbed 46-year-old community nurse Mariam Kamara four times in the face, neck and chest with a kitchen knife as she slept in her bed.

He then used petrol to start a fire to hide what he had done before blaming his 19-year-old son Ishmael, wrongly accusing him of being mentally disturbed and re-enacting a scene from the Netflix thriller You.

But jurors heard the couple’s relationship was “toxic” and Ms Kamara had repeatedly expressed fears to friends that he was going to kill her.

Jurors were also told that the defendant, who had a child with another woman, had feared she would leave him for a man she had struck up an intimate friendship with in Sierra Leone.

Koroma was found guilty of Ms Kamara’s murder and arson following a trial at the Old Bailey.

On Monday, Judge Rebecca Poulet KC jailed him for life with a minimum term of 29 years with a concurrent sentence of seven years for arson.

The judge told Koroma he had planned the murder because he did not want Ms Kamara to travel to Sierra Leone.

She went on: “You had planned to burn her body and thereby destroy the evidence of her injuries but very careful investigation and your own inconsistent statements have exposed your crimes and your undoubted responsibility for them.”

The judge said that blaming his son was a “particularly cruel and unpleasant” aspect of the case.

Other aggravating features included the fact that the killing was carried out in a background of abuse and “terrifying threats”, and that the victim’s son, then aged 17, was asleep in the house.

Contrary to the defendant’s claims, Ishmael was a “typical teenager” and Ms Kamara was a “deeply caring and responsible mother”, the judge said.

In a victim impact statement, Ishmael, who is now studying accountancy at university, spoke of how much he missed his mother and had been deeply affected by her death, now finding himself unable to trust anyone.

Previously, the court had heard how Ishmael had called emergency services in the early hours of January 24 2022 after fire broke out in an upstairs bedroom of the family home in Railton Road, Brixton, south London.

As flames and smoke gushed from a first-floor window, the defendant calmly told emergency workers that his wife was trapped inside, the court heard.

Ms Kamara’s badly burnt body was later found lying on her bed surrounded by the distinctive smell of petrol.

An empty jerry can and funnel was discarded on the ground floor and the victim’s blood was identified on bannisters near the bottom of the stairs.

A post-mortem examination concluded Ms Kamara had died from stab wounds to the neck and chest before the fire started.

The defendant denied going into the blazing bedroom yet had sustained a burn to his foot from close proximity to the flames.

An analysis of his clothes revealed heat damage caused by exposure to flames, jurors were told.

A kitchen knife stored in a block was examined and found to have Ms Kamara’s blood on it.

In a police interview, Koroma claimed he had been asleep on the sofa and was woken by the smoke alarm at 3am.

During the trial, he changed his account saying Ishmael had woken him up downstairs and he had initially lied to protect him.

Under cross-examination, Ishmael denied being unstable and killing his mother after having a bad parents’ evening.

Detective Chief Inspector Chris Wood, of Scotland Yard, said: “This was a brutal murder and an appalling act of violence against a woman.

“After murdering his wife, Koroma then started a fire to cover up his actions. This was a further selfish act which put other members of the public at risk.

“My officers conducted an in-depth investigation into this murder and worked hard to gather a range of evidence which pointed to Koroma as the killer.

“Our thoughts are with Ms Kamara’s family and friends and in particular with her son who we continue to support through this trauma.”