A TEENAGE boy has been detained in a psychiatric hospital indefinitely after killing a university lecturer with electric drills, knives and a hammer.

The teenager carried out the "sustained and prolonged attack" after following orders from voices in his head, Winchester Crown Court heard on Wednesday.

Dr Barry Hounsome died while trying to escape the attack at his home in Gosport on October 29.

The 54-year-old academic, who previously worked at Southampton and Bangor universities, researched dementia and Parkinson's disease.

The boy, who cannot be named for legal reasons, was due to stand trial for murder but the prosecution instead accepted a guilty plea to manslaughter by diminished responsibility.

Sentencing him to a hospital order under the Mental Health Act, Mr Justice Neil Garnham said: "You killed him in the course of a vicious and ferocious attack.

"The evidence suggests you are riven with remorse for what you have done.

"I have no doubt that you were at the time of the attack, and that you remain, highly dangerous.

"Without medication there's a real risk of a similar event in the future."

He told the court he believed the boy could pose a "significant risk of serious harm to the public".

Kerry Maylin, prosecuting, told the court: "This was a sustained and prolonged attack.

"He said voices in his head had been telling him to kill.

"The night before the incident the voice was telling him to kill someone and that morning, it was Barry."

The boy left a note and made a video apologising for his actions, later telling the police he first hit Mr Hounsome with a hammer, before stabbing him with knives, spraying him with ammonia and drilling into his head while he was still alive, Ms Maylin said.

During the attack Mr Hounsome - who lived with his Russian wife Natalia, a senior lecturer in global health economics at Brighton and Sussex Medical School - tried to escape but the boy "pulled him back and forced him to the floor", the court heard.

He told the police Mr Hounsome asked him "Why?" and he replied "I'm sorry".

Afterwards the voice told him "You are done" before he tried to destroy two hard drives and a tablet in the microwave, the court heard.

Mr Hounsome had several defensive wounds and his front door key was found underneath his body.

Ms Maylin said the boy said he started hearing voices around 18 months before but never told anyone about it.

Over time the voices - which adopted the accent of an Eastern European man - became "more manic, aggressive and demanding", escalating from telling him to kill animals to carrying out attacks on random people, the court heard.

She told the court the boy said: "Something in my head kept telling me to do it. I didn't want to do it.

"I tried to push myself away but I ended up doing it. I'm so sorry."

He has been diagnosed with paranoid schizophrenia and is thought to have experienced a psychotic episode just before the attack, the court heard.