A mother and son have been been handed life sentences after murdering a marathon runner who crossed their land.
Carol Dawson, 72, and Scott Dawson, 41, shot Gary Dean in the back with an air rifle and beat him with rocks and branches in a premeditated attack, a court heard.
The pair had been in a prolonged dispute with Mr Dean, after he started running along a footpath near his home in Silkstone Common, Barnsley, which ran across the Dawsons’ land.
The 48-year-old is believed to have been on the autistic spectrum.
Ms Dawson and her son previously tried to have the runner prosecuted and spread false and malicious rumours about him.
“Instead of trying to understand his problems and approach them as others had, you commenced a vendetta,” said Judge Jeremy Richardson QC.
“This involved peddling truly unpleasant rumours and starting a process of targeted intimidation against him.”
The rumours included a false accusation that Mr Dean tried to lure children into the woods with him, prosecutors said.
The dispute began in late 2016 when Caroline Dean, the runner’s wife, woke to find her car and house daubed with graffiti saying “Stay away Baz”, “paedo” and other offensive comments.
Ms Dean, a headteacher, told the court that she and her husband were regularly followed and threatened by strangers as the rift escalated.
Four youths once broke into their home, injuring the couple.
On another occasion Ms Dean’s school was falsely told she should not be allowed to work with children because her husband lured children into the woods.
A local authority safeguarding inquiry found nothing to support the allegation and the Deans eventually secured a restraining order against the Dawsons.
On 6 September 2018 the Dawsons waited for their victim and killed him, after Ms Dean had left for work.
The mother and son were convicted of murder on Friday after a five-week trial at Sheffield Crown Court.
“It is a reasonable inference that it was you, Scott Dawson, who executed the killing and took the lead,” Mr Richardson said.
“It is also a reasonable inference that you, Carol Dawson, fully participated in the killing by encouraging and facilitating the execution of it.
“The murder of Gary Dean was carried out with brutal determination.
“I have little doubt that you both encouraged the other to act.
“The venom within each of your characters permeated the other to make a truly toxic and dangerous situation.”
On Monday the judge sentenced Scott Dawson to serve a minimum of 31 years in prison, while Carol Dawson was handed a minimum sentence of 26 years.
The judge said that Mr Dean had been a warm, kind and loved man, adding: “You both, on the other hand, were filled with venom and a desire for revenge for what you, inaccurately, perceived was police inaction.
“You lost all sense of proportion and became envenomed with a desire for revenge when you thought nothing was being done to prevent this essentially harmless man from behaving in what was at worst in 2018 a mildly anti-social manner.”
Additional reporting by agencies