Matthew Daley, 35, has been found guilty at Lewes Crown Court of manslaughter on the grounds of diminished responsibility following the so-called "road rage" killing of Donald Lock, 79, in West Sussex.
The son of Roger Goswell, who stabbed his wife to death and then killed himself in a car crash, says he warned an NHS Trust that his father was a danger.
The killing is one of 10 that Sussex NHS Partnership Trust has announced an independent review into. All the killings involved people who used the services of the trust.
Roger Goswell was suffering from mental illness and had been treated for a different suicide attempt. His son Joseph Goswell says he tried to tell the trust that his father was planning to kill his mother.
The independent review of the 10 killings is in response to the death of Don Lock. He was stabbed 39 times in a 'road rage' attack by Matthew Daley, who suffered from chronic mental health problems.
Before the killing Daley's family had "pleaded" with clinicians to section him as his mental health declined.
A review has been launched into ten killings involving people who had contact with the Sussex NHS Partnership trust
The killing of Don Lock has been a tragic case for all those involved, say Sussex Police.
A man has been found guilty of killing a 79-year-old pensioner in a road rage attack.