Jurors at Cambridge Crown Court have been shown footage capturing the moments before Saudi student Mohammed Algasim was fatally stabbed in Cambridge.
The video shows Chas Corrigan, 22, wearing a high-visibility jacket, approaching Mr Algasim as he sat on a low wall outside his student accommodation on 1 August last year.
According to the prosecution, Corrigan is seen speaking briefly to the 20-year-old before walking away towards the train station. He then returns, produces a knife and advances towards Mr Algasim, who begins to run.
The court heard Corrigan followed him and stabbed him in the neck. Mr Algasim died from a single wound which severed the carotid artery and jugular vein, causing severe blood loss.
Prosecutor Nicholas Hearn told jurors the attack was random and that Mr Algasim “posed no threat to anybody”.
A fellow student, Abdullah Bin Shuail, said Corrigan shouted “What did you say?” before punching Mr Algasim while holding what he described as a large knife.
The court heard the two men had never met. Corrigan had allegedly been drinking and taking drugs earlier that evening and was described as behaving erratically at a nearby pub.
Corrigan denies murder. Defence counsel Jane Osborne KC said he believed Mr Algasim was acting aggressively and thought he was about to be attacked. She told jurors he produced the knife to wave between them and did not intend to cause harm.