A prisoner with delusions that he was a robot has been locked up indefinitely for killing a Serco custody officer by kicking her in the head as she tried to escort him from court.

Six years ago Humphrey Burke, 28, was deemed mentally unfit to stand trial over the death of Romford woman Lorraine Barwell, who died two days after being attacked at Blackfriars Crown Court on June 29 2015.

At the time Burke was handed a hospital order, after a jury in a trial of facts found he had caused the 54-year-old “catastrophic” brain injuries.

Following psychiatric treatment at Broadmoor Hospital for paranoid schizophrenia, improvements to his mental health meant that he was fit to plead.

He went on deny murder, but pleaded guilty to manslaughter by reason of diminished responsibility at the Old Bailey on December 23 last year.

Burke was sentenced to an indefinite hospital order yesterday - January 11 - by the Recorder of London, Judge Mark Lucraft QC.

He was due to be sentenced for separate offences on the day of the 2015 attack, having admitted arson and attempting to rob two bookmakers eight months previously.

Burke had smashed up the security screen at Ladbrokes in King's Cross Road with a claw hammer on October 15 2014, after a cashier refused his demand for cash.

He then set fire to the William Hill in Newington Green Road four days later after dousing the counter with a flammable liquid.

Burke warned the cashier: "Give me the money or I'll blow the f***ing place up. I''m not f***ing joking."

He accidentally burned his own gloves in the process, and trapped staff behind the counter.

Concerns for Burke’s mental health and propensity toward violence had been raised before his attack on Ms Barwell, who had worked as a custody officer for Serco for more than 10 years.

A colleague of the fallen custody officer described how Burke had pulled his leg back and kicked Ms Barwell in the face before he could be transferred to a prison van.

The court heard Burke suffered from a delusion that he was a robot acting under an “external force” at the time.

Martin Lock, a consultant forensic psychiatrist, explained how Burke had told him "he had been forced to kill Ms Barwell by the outside agency who controls his behaviour as a robot".

"It was somewhat difficult talking to Mr Burke because he was extremely irritable and he told me very early on he could tell I agreed with all the other psychiatrists who assessed him."

Mr Lock added Burke was "annoyed I did not accept that he wasn't a robot".

Ms Barwell’s daughter and sister read out their victim impact statements to the court, describing the loss of the much-loved mother and grandmother as "emotional torture".

Her daughter broke down as she told the court: “Humphrey Burke will never be able to comprehend the damage done to my mum or my family.

“As a family, no sentence will ever be enough to compensate the loss we have suffered.

“He still took a life. He does not – and should not – be allowed to forget that as we never will.”

Her aunt went on to describe how they "will never be able to celebrate birthdays and Christmas again".

She said: "The old cliché says that time is a great healer, but the reality is time brings even more pain.

"I have a constant feeling of being unsafe. If this could happen to my sister at work it can happen to anyone."

She continued: "As a family we have heard so much about Humphrey Burke's needs and requirements.

"Our reality is he had a history of violence way before this happened. We will never accept manslaughter - we will only ever accept it as murder."

Sentencing, Judge Lucraft said the events surrounding Ms Barwell’s death were “terrifying and appalling”.

He rejected a penal element to the sentence in light of his mental state, saying assessment and treatment was “key" to controlling the risk to himself and the public if he stopped taking medication - which would not be compulsory in prison.