30 August 2012 Last updated at 09:19 ET

Jamie Simpson pays tribute to murdered father James

Jamie Simpson said his mother Minnie had been left "shattered, nervous and a lonely widow" after the murder of his father James

The son of a man who was murdered by a car thief outside his South Lanarkshire home has paid tribute to his "brave", "moral" and "compassionate" father.

Jamie Simpson said the death of his father James had left his mother Minnie a "shattered, nervous, lonely widow".

Christopher Grenfell, 25, was convicted of murdering Mr Simpson, 76, outside his home in Ashgill in November 2011.

At the High Court in Glasgow, he was jailed for life and ordered to serve a minimum of 17 years in prison.

In a statement released by the Crown Office, Jamie Simpson said: "My father was a man filled with passion and compassion in equal measures.

Contented couple

"He cared sincerely about people and would not hesitate to offer help and advice to anyone where he was in a position to help.

"He met life with a positive and unquestioning optimism and, together with my mother, Minnie, had achieved a deep state of contentment in their later years."

Mr Simpson said that his father "had a strong sense of right and wrong and pursued his morals through his actions at all times".

He said: "This combined with his bravery, resulted in his pursuit of the individual who decided it was his right to take property belonging to my mother and father.

"Christopher Grenfell decided to counter the actions of my father by committing the murder of a 76-year-old man when he had the clear option of simply driving away.

"In the wake of this choice, he not only left a man dying in the street, but also left his wife absolutely devastated."

Mr Simpson said the death of his father had turned his mother from "a happy, confident and independent woman" into a "shattered, nervous and a lonely widow".

He said: "Every situation that occurs and every day of her life my mother always includes the phrase 'If Jimmy was here'."

"This is the sentence that Christopher Grenfell has handed to my father, mother and me."

'Tragic and needless'

Mr Simpson also paid tribute to Strathclyde Police and Crown Office officials for their "committed professionalism" and "genuine compassion and empathy" during what had been an "extremely difficult" time for the family.

Speaking after Grenfell was jailed for murder, West of Scotland procurator fiscal John Dunn said the case involved the tragic and "needless loss of life of a man who was simply trying to protect his property".

"Christopher Grenfell has been found guilty of breaking into Mr and Mrs Simpson's home to steal the keys for their Land Rover and then, with William MacVicar, stealing that vehicle," he said.

"Their utter disregard for the safety or property of others has led to this murder.

"A family has been robbed of a husband and father for no reason other than selfishness and greed."

Det Supt Robbie Allan, of Strathclyde Police, paid tribute to the Simpson family who he said had "displayed real strength and dignity" at "the most terrible time of their lives".

"This was a particularly callous murder where Grenfell put greater value on his acquisition of a car than the life of an innocent man simply protecting his own property that he had worked so hard for," he said.

"I hope this conviction can bring some small comfort to Mrs Simpson in particular, who had to endure watching her husband lose his life."