Stephen Whitehead (49) was found slumped in his favourite chair in the canteen at Pendle Skip Hire in Burnley, after being attacked by Aaron Jenkins - a casual worker who had been sacked following a fight with Mr Whitehead.
Jenkins (20), of Burnley, admits killing Mr Whitehead in an act of revenge after breaking into the yard and discovering him sleeping in the canteen, when the site was shut overnight.
He told police he had broken into the yard to steal a motorbike but when he heard a radio playing in the canteen, he said: “I had a look in and I saw Stephen Whitehead and thought this is my time to get him back, like payback kind of thing.
“I’ve seen something, like a sledgehammer, I’ve picked it up, gone back to the canteen. At that point, I’ve smacked him a couple of times with it, then just walked off.”
Jenkins, who has moderate learning difficulties, denies murder but admits manslaughter on the grounds of diminished responsibility.
Mr Whitehead was found by colleagues who opened up the site around 7am on Monday, July 27th, last year.
As Graham Bennett waited for someone to open the gate, he saw Jenkins, who he recognised as a casual worker who had been at the site some weeks before.
He started talking about a fight with Mr Whitehead, saying it had started because Mr Whitehead had called him lazy.
The fight, on July 10th, which resulted in both men needing hospital treatment, was witnessed by other workers at the yard, who said there had been a simmering argument after Jenkins had been accused of not pulling his weight while separating waste on a conveyor belt.
Opening the trial at Preston Crown Court, Francis McEntee (prosecuting) said: “As a consequence Aaron Jenkins had been put to work in the yard with Stephen Whitehead. It was not long before Stephen Whitehead also criticised Aaron Jenkins for being lazy, resulting in insults and threats being exchanged, before Aaron Jenkins took off his shirt and began bouncing around like a boxer, threatening to knock out Stephen Whitehead before punching him.”
Both men were injured during the scuffle when they fell onto some porcelain. As Jenkins’ arm bled, he continued to threaten Mr Whitehead.
Following the fight, manager Chris Gorton told Jenkins not to come back to work at the site.
Other workers suspected Mr Whitehead had been sleeping in the canteen as he never accepted a lift home and would wash and change at work.
When Jenkins broke in on the night of July 25th and saw Mr Whitehead asleep between two chairs, he collected a sledgehammer from the office and rained down five or six heavy blows to Mr Whitehead’s head.
He said: “I was a bit drunk. I thought payback time.”
Mr McEntee said: “Aaron Jenkins has moderate learning difficulties - that is not disputed. The issue in this case will be whether this abnormality diminishes his responsibility for killing Mr Whitehead so he should properly be convicted of manslaughter as opposed to murder.
“It will be asserted the defendant’s abnormality of mental functioning substantially impaired his ability to exercise self control and secondly this abnormality provides an explanation for his actions in killing Mr Whitehead.”