Serial killer Daniel Gonzalez was an intelligent but troubled child who turned into a man who needed help he was never given, according to his mother.
Daniel Gonzalez murdered four people and tried to kill two others
Lesley Savage said she and her son had made "incessant pleas" for help over many years to health services, social services and the police.
But the jury in the 25-year-old's murder trial decided the killing spree which saw him murder four people had not been caused by a mental illness.
And the health trust responsible for his care said after the guilty verdict the "appalling events" he carried out could not have been predicted or prevented.
Gonzalez, 25, from Woking in Surrey, killed two women in Sussex and two men in north London within the space of three days in September 2004.
Ms Savage, who said she extended her "sincere condolences" to the families of those her son killed, separated from his father when Gonzalez was six.
She said as a child he was a bright but troubled boy who excelled at sport, drama and languages and had a very high IQ but had problems talking to people.
She said he was "extremely intelligent but extremely disruptive".
"He could be absolutely charming but could also be manipulative. We had some terrible arguments.
"I could not cope with his violent abusive arguments.
"He was a chronic bed-wetter until the age of 12.
"At nursery school he had good speech and was good at sums but lacked social skills and did not know how to play with other children.
"Because he was so intelligent, other boys tended to bore him."
Ms Savage said when her son was about nine, he once came downstairs with his arms at the side of his head, saying: "Mum I cannot carry my head - it is too big."
Ms Savage said as her son became older and had problems she had made numerous attempts to get help for him.
She said: "Despite our incessant pleas to health services, social services and to the police, Daniel was often turned away, passed from one group of professionals to another and left without the support and help he so obviously and desperately needed."
Victims Derek and Jean Robinson, Kevin Molloy and Marie Harding
She said phone calls had gone unanswered, notes had gone missing and various people had told her they could not help or had passed her on to someone else.
"We met individual decent, caring professionals who were dedicated and hard working, but even they could not sustain any support over time as Daniel was moved from one service to another," she said
Ms Savage said she had written a letter to social services at one point, asking: "Does my son have to commit murder to get help?"
And Ms Savage said her son had himself written a letter to his GP begging for help.
The letter, which he took to the doctor by hand, said: "Please, please, help me, this is very urgent.
'Shocked and horrified'
"I really, really do need medical help to find the correct environment and the correct medication."
Ms Savage said: "Every time we asked for help... we were told we would have to wait for a crisis to occur before he could have the help he needed.
"I did not know something dreadful was going to happen, but I was scared."
An inquiry into Gonzalez's care and treatment is to be carried out by the NHS.
After the verdict, the NHS trust which treated Gonzalez for seven years said in that time there was "no sign" that he would show serious violence towards others.
A statement from the Surrey and Borders Partnership NHS Trust, which took over from the North West Surrey Mental Health Partnership, said: "Everyone who was involved in his care was shocked and horrified to hear that he had been charged with these dreadful offences.
"The Trust offers its sincere sympathy to the families of Mr Gonzalez's
victims and understands from the jury's verdicts that they believed that his
mental illness was not a factor in the attacks.
"These incidents were not preceded by a history of violence and for that
reason the Trust does not believe his actions could have been predicted."
Trust chief executive Fiona Edwards said there was no direct link between Gonzalez's illness and his "shocking attacks".
"Mr Gonzalez was a disturbed young man who acted as he did from forces that we may never fully understand," she said.
"If there are any lessons we can learn that will in any way reduce the
likelihood of this kind of tragedy happening again we certainly want to discover them."