A “wicked” man, jailed for life for murdering his young son, his estranged wife and her father by setting fire to their Chatham home, can have no complaint about his minimum 37-year jail term, judges have ruled.

Danai Muhammadi, 26, recruited his girlfriend, Emma Smith, 23, and a Maidstone bouncer to help start the blaze which killed his wife, Melissa Crook, 20, their 16-month-old son, Noah, and his father-in-law, Mark Crook, 49, in 2011.

Muhammadi was jailed for life and ordered to serve at least 37 years behind bars by Mr Justice Sweeney at Maidstone Crown Court in June, 2012.

It comes after he was found guilty of three counts of murder and two of attempted murder.

Smith was handed 14 years after she was convicted of three counts of joint-enterprise manslaughter.

Three of the country’s most senior judges at London’s Appeal Court rejected sentence challenges by the pair, saying “there is nothing” in claims their jail terms were too tough.

Lady Justice Rafferty said Muhammadi and his friend, Farhad Mahmud, 36, of Fernhill Road, squirted petrol through the letterbox of the Crooks’ family home, in Chatham Hill, in the early hours of September 10, 2011 before setting it alight.

Noah and his mother died in the fire, with Mr Crook passing away a week later as a result of his injuries.

Miss Crook’s mother, Amanda, 51, and brother, Bohdan, 23, survived despite “life-threatening injuries”.

Smith, who was “besotted” with Muhammadi, had driven with him from Coventry to Kent and sent abusive phone messages to his estranged wife in the hours leading up to the fatal attack, Lady Justice Rafferty explained.

It was she who called 999 from an unregistered mobile phone to report the blaze shortly after Muhammadi and Farhad had sparked it using a garden spray.

Lady Justice Rafferty said Muhammadi and Miss Crook, who married in 2009, had earlier split amidst acrimony and she returned from the Midlands to live with her parents in Chatham.

In the months leading up to the murders, Muhammadi told work colleagues he was thinking about harming his wife and, the day before the arson, he said his wife and child had been hurt in a fire.

When workmates asked if he had anything to do with it, he said “maybe” before explaining that he was “going to finish the job”.

Smith borrowed a large garden spray from a neighbour and the pair drove to Maidstone where they met Mahmud at his flat. From there the two men drove off in the bouncer’s car, the appeal judge said.

The men sprayed the fuel through the Crooks’ letterbox, dousing the foot of the stairs so no-one could escape, before lighting the killer blaze.

After his arrest, Muhammadi, from Coventry, expressed feigned “shock and surprise” and denied any involvement. He later insisted he had only travelled to Chatham to confront a made-up blackmailer he claimed had threatened to kill his wife and child.

Smith said at first she had been in Coventry at the time of the attack but later changed her story, saying she had gone along to Kent, but had not known that the men planned to commit a dangerous fire attack.

Mahmud received a life sentence, with a minimum 34-year-term, after he too was convicted of three counts of murder and two of attempted murder.

Mr Justice Sweeney had said that Muhammadi acted out of “pure selfish wickedness” born from “anger, spite and resentment”, and that he later showed “not a spark of genuine remorse” for what he had done.

He added that Smith, from Coventry, had known, at the least, that the men intended to cause serious harm when she carried out her part and later “told lies on an epic scale”.

On appeal, Tim Barnes QC, for Muhammadi, argued that the judge “double counted” certain factors and wrongly held that Noah was a “vulnerable” victim in coming to an “excessive” minimum term .

But Lady Justice Rafferty, sitting with Mr Justice Cranston and Mr Justice Stewart, said: “We make it perfectly plain that it is our view that there is nothing in any of the submissions. We reject all the submissions and this appeal is dismissed.”

The judge also rejected a sentence challenge by Smith, dismissing claims by her barrister, Alan Kent QC, that Mr Justice Sweeney failed to take proper account of her “chaotic and disturbed background” and her lack of intelligence.

She concluded: “The difficulty attached to that submission as to her personal mitigation is that the sentencing judge plainly took account of it, going on to say that, notwithstanding all of it, she had known her own mind.”

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