Judge Maria Lamb, sentencing Welsby to eight years in prison with an extended licence period of five years, said: "You told the probation officer on January 15 that you were 'angry at the world' and stabbed the 'first person you saw'."
She said she believed he had, in fact, waited in a secluded spot for 'prey' – someone vulnerable and alone. She added: "It is a chilling feature that you have behaved throughout the incident with a sophistication and calculation which belies your years."
She pointed to the fact the weapon had never been recovered nor his clothes from the day, and that GPS on his phone had been either turned off or deleted.
She also referenced psychiatric reports that mentioned he experienced 'intrusive thoughts' about 'physical and sexual violence' towards himself and others....you'll be seeing him again in about 5 years time. Probably when he's killed someone after early release.