An inquest into the frenzied stabbing of a pensioner by his schizophrenic son has concluded after questions were asked as to whether medical staff could have done more to prevent the tragedy.

Legal experts argued their final cases to coroner Roger Hatch today – the sixth day of the inquest into the killing of Terry Wotton, 71.

He died at his home in Mackenzie Way, Gravesend, after being stabbed 10 times by his mentally-ill son, Tony Wotton.

The coroner heard how a lack of knowledge into Tony's violent past among visiting mental health professionals may have contributed to their decision not to admit him back to hospital.

The reasons given for this lack of awareness included the use of external doctors not familiar with Tony's case, and that there was insufficient information of the patient's history made available to those doctors.

In his final submission to the coroner, Tony's brother-in-law Peter Ludlow, who has represented Mr Wotton's family throughout the hearing, said: "The death of Terrence Wotton was not just avoidable or preventable, but needless and unnecessary.

"We believe the evidence has adequately proved this."

However, representatives of the doctors directly involved in Tony's treatment all argued that there was insufficient evidence to say that if they had acted differently Mr Wotton's death could have been avoided."

"Tony was holding the knife in a downward position within a couple of feet of Terry. It happened so quickly and was very frenzied. I shouted 'leave him alone'..." - Emma Wotton

Stephanie Clarke, assistant director of Social Care & Partnerships for West Kent, told the inquest that several changes had been made so that visiting mental health doctors were made more aware of a patient's medical history, including ensuring an additional member of staff gathers information on a patient's history before assessment.

The case has resulted in a wider investigation being conducted by NHS England to prevent similar incidents happening nationwide.

Last week, the coroner's court heard how in the several weeks leading up to Mr Wotton's death on September, 12, 2011, Tony had refused to take any medication, leading to threats by doctors that he may be re-admitted if he continued to deny treatment.

Despite visits by mental health professionals to conduct a risk assessment of Tony's case, no action was taken and he continued to live at home with his parents.

Doctors who assessed Tony in the weeks leading up to the fatal stabbing of Mr Wotton had only a limited awareness of the extent of his history, which included the brandishing of a knife in front of his father and the stabbing of work colleague.

The inquest at Gravesend's Old Town Hall began on Monday, September 22 into the killing of Mr Wotton, who was born in Dartford and was married to Emma Wotton, better known as Joan.

In a statement read out on her behalf last week, Mrs Wotton described her husband as "well liked and a wonderful husband and cook" who was also a keen golfer.

A post-mortem examination, conducted by forensic pathologist Dr Olef Biedrzycki at Darent Valley Hospital, found that Mr Wotton suffered stab wounds to his back, left forearm and above his right knee.

Dr Biedrzycki stated: "There are no other natural diseases that may have caused or contributed to the death."

One of the most significant wounds to Mr Wotton was to his left forearm which was as deep as 16cm.

Recalling the night of the killing, Mrs Wotton said in a statement: "I was woken up when I heard Tony shout up the stairs 'get up you evil thing you'."

"He was aggressive, abusive, nasty in his aggressiveness especially towards my dad. Six to eight weeks after he stopped taking his medication you would see the aggressiveness coming in..." - Diane Ludlow

"First thing I saw was Tony holding a knife. Tony was holding the knife... in a downward position within a couple of feet of Terry.

"It happened so quickly and was very frenzied. I shouted 'leave him alone'.

"Tony then ran down the stairs. I think he realised what he had done.

"Terry has always felt that at some point Tony would harm him and was always dubious of him."

On September 10, 2011, a team of mental health professionals visited Tony and said they had no grounds to admit him back to hospital, according to Mrs Wotton.

The inquest heard how Tony's struggle with mental illness became visible in his teenage years.

His sister Diane Ludlow said: "As he got older he got bullied quite often. He never really discussed it but I would always intervene if I was around to stop it within school.

"He had difficulties with his sexuality. At first, he wouldn’t accept it and wouldn't discuss it. I don't think he wanted to be gay but he didn't have a choice at that time.

"He became tearful and said he could see colours and was making strange comments. He said he could see spiders crawling over him and snakes and that sort of thing."

In adulthood, Tony had a number of violent outbursts. This included stabbing someone in the arm at his workplace at Lambeth Council, and threatening his father with a knife in 2007.

The former outburst led to a dismissal from his position as a clerk, but was not reported to the police. Soon after he was diagnosed with paranoid schizophrenia.

On several occasions, Tony refused to take his medication believing he did not need it.

Describing what Tony was like when he was not taking his medication, Mrs Ludlow said: "Aggressive, abusive, nasty in his aggressiveness especially towards my dad.

"Six to eight weeks after he stopped taking his medication you would see the aggressiveness coming in."

Coroner Roger Hatch is due to record a verdict on Wednesday.