'Violent fantasies'

The court heard Talbot-Lummis was obsessed with guns and violent computer games.

Judge Levett said the defendant had played a virtual reality computer game called Blood Trail the day before the shooting.

A friend of the defendant said the game was "hyper-realistic in its violence", and that Talbot-Lummis "adores it".

The judge told the defendant: "You had this obsessive interest in all kinds of firearms and had become entrenched in watching computer games online."

Talbot-Lummis had been "playing games in a virtual world more suitable for 18-year-olds", the judge added.

He said that playing such games "was a factor for the onset of violent fantasies you had".