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A student has been jailed for life for stabbing his guardian to death in what a judge described as a "frenzied attack of enormous brutality".

David Quartey knifed Dr Victoria Anyetei 57 times while she sat in her car on the driveway of her house in Teynham Road, Dartford, in August last year.

A jury of eight men and four women took over 11 hours to unanimously find the 22-year-old guilty.

There were shouts of elation from the public gallery as the verdict was passed at Maidstone Crown Court on Thursday. Quartey held his head in his hands before being led away from the dock.

Recommending a minimum prison term of 15 years, Judge Jeremy Carey said the consultant paediatrician's murder resulted from "an episode of uncontrollable rage".

He added: "It was a frenzied attack of enormous brutality - 57 stab wounds which went deep into her body and each capable by itself of ending her life."

• Audio: Listen to senior investigating officer Det Supt Anne Brittain speaking to kmfm >>>

Dr Anyetei, 54, was on her way to work at St Thomas's Hospital in London when Quartey attacked her.

The student, of Humber Road in the town, denied murder, claiming he had not been the attacker.

But the court heard he killed Dr Anyetei on August 14 last year while under pressure from failing vital examinations in his quest to become a lawyer.

She had discovered he had lied to her about receiving his exam results and was about to report back to his parents in Ghana.

At the time of the murder, Quartey lived with Dr Anyetei and her son Andrew Thompson.

Mr Thompson was in court to see the sentence passed. The judge added: "You have deprived a son of a loving mother."

In a statement released through Kent Police, Dr Anyetei's brother Jonathan said the family were happy with the verdict and pleased that justice had been served on behalf of Victoria.

Mr Anyetei said: "On behalf of the family, I would like to thank the police for all their hard work in helping us to find closure to this sad event."

• Video: A police family liaison officer reads the statement outside court on the right of this page.

Describing the investigation as complex, senior investigating officer, Det Supt Anne Brittain, said: "This was a challenging case to investigate as there was initially no clear motive or suspect.

"Dr Anyetei led a professional and relatively simple life which revolved around her family, church and work."