A mother and son killed a marathon runner following a “vendetta” over his use of a public footpath that crossed through their land, a court heard.

Gary Dean was beaten to death by Carol and Scott Dawson after he was ambushed as he exercised on Sep 6 last year in Barnsley, South Yorks.

The pair showed no emotion as they were found guilty at Sheffield Crown Court on Friday and were warned they would be jailed for life when they are sentenced next week.

The unemployed 48-year-old was attacked with rocks and tree branches, after being shot in the back with an air rifle, before his body was dumped in a ditch off Silkstone Common.

Sheffield Crown Court heard Mr Dean, who completed the London Marathon 18 times, became embroiled in a “vendetta” with the Dawsons for repeatedly running on their land during his morning training regime.