
A patient who wrongly blamed a GP for his father's death has been found guilty of attempting to murder the doctor with a crossbow.
Mark Waterfall, 46, said "you killed my father, I am going to kill you", as he shot Dr Gary Griffith at Suthergrey House Medical Centre in Watford.
The GP survived the attack last July as his untucked shirt had been gathered around his abdomen.
Waterfall told St Albans Crown Court he had not meant to harm the doctor.
Five days before the attack the defendant's father, Terence Waterfall, had gone to see Dr Griffith complaining of breathlessness.
The GP arranged for fluid to be drained from his patient's right lung in hospital, but it was discovered he had lung cancer and he died the next day.
A three-day trial heard Waterfall had become convinced Dr Griffiths was responsible for his father's death.
'Dejected'
On 10 July he went to the surgery in St Johns Road with the crossbow hidden in two plastic carrier bags.
"He stepped into the room and was pointing something at me," Dr Griffith said.
"He said, 'you killed my father and I am going to kill you'."
After firing the crossbow, the court was told, Waterfall dropped the weapon and left.
Dr Griffiths said the defendant looked "dejected" when he realised he had failed to kill him, saying afterwards: "I can't even get that right."
The doctor pulled the bolt from his abdomen and followed Waterfall to the surgery's car park.
"I tried to persuade him to go to the police station round the corner. I said I will come with you," he said.
He said Waterfall replied he had "murdered" his father.
Giving evidence, the defendant told jurors he had not meant to harm or kill the doctor.
He claimed he took the crossbow with him to the surgery because he wanted to "scare Dr Griffith" and denied saying he wanted to kill him.
Waterfall, of Fairhaven Crescent, South Oxhey, had admitted a charge of wounding with intent at the start of the trial but pleaded not guilty to attempted murder.
He will be sentenced on 8 February and was warned by Judge Stephen Warner it was "inevitable" he would receive a "significant" sentence.