Stapleton approached Bidve and his friends in the street in Salford and asked them at least once what the time was.
One of the group answered and without warning Stapleton produced a gun, put it to the head of Bidve and fired a shot, which killed him, the court was told during the trial that is expected to last 12 days.
The Bidve family has travelled from Pune to attend the trial.
Opening the case, prosecutor Brian Cummings told the Crown Court, "Anuj Bidve immediately fell to the ground, fatally injured. The gunman smirked or laughed and ran off." He told the jury that Stapleton had pleaded guilty to his manslaughter three weeks ago but continues to deny murder.
The defence is likely to call expert psychological and psychiatric evidence in the trial.
Cummings added, "I will ask you to keep in mind as we go through evidence in this trial is that Kiaran Stapleton's eventual admission that he is the killer came at an advanced stage of proceedings, and only after a significant body of evidence had already been gathered against him."
Bidve, who was a student of Microelectronics at Lancaster University, was on his way from his hotel walking through Ordsall to the Boxing Day sales in Manchester city centre with a group of other Indian students when he was killed.
The Crown Court was told during the day's proceedings that on the day after the shooting, Stapleton, who described himself in January as 'Psycho Stapleton', checked into a hotel near the scene of the crime. He was with a friend, Ryan Holden, at the scene of the shooting.
Holden was initially arrested as a suspect, but he is now due to appear as a witness for the prosecution.
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