Student carried out a 'cold-blooded execution' of university housemate by 'ambushing him and stabbing him 30 times' in their garden after rows about rent, court told

A masked university student lay in wait for his housemate to return home before stabbing him 30 times to death, a court has heard.

Zack Coughlan, 23, dressed all in black and wore a mask and gloves to ambush Jamie Collins, 21, in the garden of their home in Filton, South Gloucestershire.

A jury was told that Coughlan and Mr Collins were both final year students at UWE Bristol and lived together in a house owned by the defendant. The prosecution described the attack as a 'carefully planned and cold-blooded execution'.

The pair were said to have previously rowed over the amount of rent Coughlan was charging Mr Collins.

Mr Collins was stabbed repeatedly and Coughlan left him dying in the alleyway as he cycled away on his housemate's bike, Bristol Crown Court was told.

Coughlan, of Cleve Road, Filton, is said to accept that he killed Mr Collins, but he denies murder. 

The student was attacked shortly before 6pm on April 8 this year after returning from university, where he was studying robotics alongside his killer.

Coughlan then dumped the bike at a nearby retail park, bought a change of clothes and threw his bloodstained clothing in a pond.

He then returned home to the house they shared on Cleve Road at about 9pm, put a pizza in the oven and did some online gaming with friends.

Adam Vaitilingam KC, prosecuting, told the jury: 'A few hours later he decided it was time to call the police and pretend that he had just found his friend's body in the garden.

'At about 2am – eight hours later – the defendant called 999. He said that his friend had been stabbed. They told him to do CPR until paramedics arrived and he told them that he was.

'Shortly afterwards armed police officers arrived. They saw Jamie's body in the back garden of the house.

'They spoke to the defendant. He told them that he had been out, at the park, and he had just come home.

'He had noticed that the back gate was open so came outside and it was then that he found Jamie lying in the garden.'

The court heard the attack was caught on CCTV installed at the house they shared, which Coughlan showed officers who initially treated him as a witness.

Mr Vaitilingam told jurors it was the prosecution case that the masked attacker was Coughlan.

He said the defendant's blood had been found on Mr Collins's bike, and analysis of his mobile phone matched the killer's movements afterwards captured on CCTV.

'The investigation showed clear evidence that it was Zack who had been the man who had waited for Jamie and then stabbed him to death before cycling away,' he said.

'And so Zack went from being a witness to a suspect in the murder. He was arrested and interviewed by the police.'

Coughlan had injuries to his hands, and he told people who saw him bleeding that he had been climbing trees and had fallen and hurt himself.

Mr Vaitilingam said there had previously been disagreements between the pair about paying rent and whether Coughlan was charging too much, but they had been resolved.

'There was nothing that any of the friends were aware of that seemed to be a significant problem,' he said.

'They hung out together both in person and online, they did gaming together, they went out together, entirely normal student life.'

The trial continues.