The mother of a mentally ill man accused of murdering another motorist broke down in tears as she revealed failings by health professionals in treating him.

Lynda Daley said her family raised numerous concerns with doctors over the years telling them they did not think Matthew Daley, 35, had been properly diagnosed.

And she told how they had "pleaded" with mental health experts to section him to protect himself and others before he went on to fatally knife Donald Lock, jurors heard.

At Lewes Crown Court, she agreed that the day her son allegedly murdered Mr Lock was "the day that all your nightmares came true".

She told how Daley had huge debt problems and his relationship with his girlfriend had broken down recently, leaving him "distraught".

Mrs Daley said: "We were never provided with a proper diagnosis. We were frequently in meetings but we were not listened to."

She added: "It's been continual over the last 10 years. In the past 10 years we have pleaded to people, it has been on a regular basis.

"It would be weeks and weeks where we would be at high anxiety about where he is."

She would listen to the radio on her drive into work fearing news about an incident relating to her son would emerge.

And the court heard that last week, the chief executive ofSussex Partnership NHS Foundation Trust wrote to her family apologising, saying the care for Daley "should have been better".

Of the apology, Mrs Daley said: "It's 10 years too late."

Daley is accused of murdering Mr Lock, 79, by knifing him 39 times in a "ferocious" attack on the A24 at Findon, near Worthing, West Sussex, on July 16 last year.

The attack happened after Mr Lock, who was returning from a cycling meeting, crashed at about 16mph into the back of Daley's Ford Fusion after Daley made an emergency stop.

Daley allegedly shouted at great-grandfather Mr Lock as he stabbed him while remaining calm "like Jesus Christ".

One witness said Daley, who is being held in a medium-secure unit after suffering mental health problems for 10 years, looked "expressionless" during the attack, like he was "having a passport photo" taken.

Another told jurors how the pair engaged in a bear hug in the carriageway as Mr Lock struggled to fend off the "flailing punches" from Daley who sped off after the attack.

Brighton and Hove Albion season ticket holder Mr Lock, who had recently been given the all-clear from prostate cancer, died at the scene.

Daley's defence team will claim that he was not acting unlawfully as he might have been acting in self defence after claiming Mr Lock was angry and aggressive, jurors heard.

The court has heard he had been suffering mental health problems for 10 years and his family had been "constantly on the case" of clinicians to get him the treatment he needed.

Daley, formerly of St Elmo Road, Worthing, denies murder. The case continues.

Mrs Daley told the court she feared her son was involved when she turned on her television and saw that the killing happened in Findon.

She tried unsuccessfully to get hold of Daley, then headed to the stables where he worked and found his damaged car parked there.

As a result of seeing the dented vehicle, Mrs Daley said her family decided to go to Worthing police station where Daley called her just as she was about to enter.

Daley told her: "I need to know where you are and that I can trust you."

He then said he had done "something really bad or something really wrong".

In a quiet voice, he went on: "I killed someone", before adding: "I want you to think about what I just said and ring me back in 10 minutes."

After going into the police station, Mrs Daley did not disclose to her son where she was and later officers were directed to him, and he was arrested at around 2pm on July 17.

Mrs Daley said Daley would often hear voices and hold his head "as if he was about to explode". And he would at times grab the steering wheel while she was driving, causing her to swerve, she said.

In an attempt to help his condition, Daley would run a couple of marathons a week, spending hours on the Downs and often taking his pet goats on his long treks.

She said: "Matthew frequently interpreted other people's actions in the complete opposite way that you and I would."

Mrs Daley told the court that the week before the killing had been particularly difficult for her son.

And, recalling the moment she realised her son was suspected of killing Mr Lock, she fought back tears as she said: "I felt physically sick.

"I couldn't believe it but, because of where it was, my heart sunk and all I kept thinking was 'We tried our best'."

She said the family had tried "so desperately" to get him the help he needed.

Daley's younger sister, Rebecca Daley, described the killing as "everything we feared would happen over the last 10 years".

In court, she agreed that her brother never really told the authorities he needed more help than he was getting, saying he did not want to be labelled.

Days before Mr Lock's killing, Ms Daley recalled seeing her brother in a mental state she had not witnessed for some time, she told jurors.

She said: "I hadn't seen him like that for a long time. On that particular day, he seemed nervous and anxious, in his manner and the way he spoke to mum.

"I was quite angry with him because I hadn't seen him like that for a long time. 

"He was always asking for so much help. I wasn't aware of his well-being and his illness." She said Daley had been ill her whole adult life.

And she added: "He has such an ability to love."

The court heard that while he was in police custody he was kept under constant watch.

In one disclosure to a police officer, Daley said that "when I drive, people try and break into my thoughts", the court was told.

And in another, Daley said to the officer: "It's sad that I had to kill someone who was so aggressive to me when I wasn't aggressive at all."

Consultant forensic pathologist Dr Nathaniel Carey said the cause of Mr Lock's death was a stab wound to the aorta.

He said that wounds may have been inflicted while Mr Lock lay dead or dying, adding that unconsciousness would have been rapid.