A man who witnessed a savage attack on an elderly neighbour by a "deranged thug" screamed at a judge: "One day he will kill somebody!"

David Lewis had found his neighbour Robert Holbrook beaten up in Folkestone and armed himself with a hammer for self-protection.

The 47-year-old was in the public gallery at Canterbury Crown Court to watch Matthew Green receive a five-year extended jail sentence for the assault, including an immediate prison term of three years.

Green had carried out a savage assault in which he rammed an electric heater and a glass into his victim’s face in October last year.

But as the 35-year-old, of Shepway Close, Folkestone, was being led away, Mr Lewis shouted at Judge Adele Williams: "Can I just say ma'am, and sorry for interrupting, but one day that man will kill somebody.

"Three years is a joke. It's a joke. If I'd have known it was only going to be three years I would have hit him with the hammer myself."

Mr Lewis was then ordered out of the public gallery by the judge.

John O'Higgins, prosecuting, had earlier told the court: "This was a particularly serious and sustained assault on an elderly man at his home."

He said Mr Holbrook had met Green and asked him to get some cannabis and the two smoked the illegal drug before "parting on good terms".

The following day, Green returned with a female "who had already had a considerable amount to drink" and went upstairs to sleep.

Mr Holbrook and Green remained downstairs, but "after about an hour things suddenly changed", the prosecutor said.

"[Green] demanded £160 and hit Mr Holbrook in the face with a clenched fist.

"He then jabbed his victim in the eye with his finger, causing pain and drawing blood."

Green then grabbed Mr Holbrook around the throat, "causing him to fear he would lose consciousness" and told him: "I will kill you!"

"Three years is a joke. It's a joke. If I'd have known it was only going to be three years I would have hit him with the hammer myself..." - witness David Lewis

The victim would later tell police: "He seemed deranged and in that state I thought he could kill me."

Green then picked up a tall glass tumbler and pushed it into his victim's face and started twisting it, saying he would maim and blind him before threatening to burn down the property.

Mr O'Higgins added: "Green continued to rant and rave before picking up a tube from a vacuum cleaner and hitting his victim over the head and then kicking him in his nose.

"He then took an electric heater, which was plugged in, and rammed it hard in his victim's face."

Green then went upstairs to the woman, who returned a short while later, asking Mr Holbrook to order a taxi for her.

It was at this point the victim called his friend Mr Lewis, who arrived 30 minutes later "and was horrified by what he found", the prosecutor said.

Mr Lewis picked up a hammer and tried to prevent Green from leaving, but was grabbed in a headlock and climbed out of a window.

Green found himself locked in a conservatory, where he was arrested by police officers as he tried to hide under dust sheets.

Peter Forbes, defending, said: "On any view this was an ugly and appalling incident. He is disgusted by himself."

Judge Adele Williams told Green, who had sat with his head bowed during the sentencing hearing, she would pass an extended sentence as "it is clear you pose a serious risk to the public".

She jailed him for 40 months for assault causing actual bodily harm and common assault, which he had admitted, and extended the licence by another 20 months, making the sentence five years in total.

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