LONDON (AP) – A 17-year-old Welsh teen has been sentenced to at least 11 years in prison after being convicted of plotting an Islamic State-inspired attack on various targets including a Justin Bieber concert.

Judge Mark Wall on Friday sentenced Lloyd Gunton to an indeterminate sentence after concluding he had a total “disregard for human life.”

Evidence during his trial showed that Gunton had researched several targets in Cardiff, the Welsh capital, including a shopping centre and Bieber’s performance on June 30, 2017. The teen lives in Llantrisant in south Wales.

At the sentencing, Wall said, “it’s not possible to estimate how many people would have been murdered or seriously injured by your actions, as the attack was foiled.”

Gunton, who suffers from an autism spectrum disorder, was convicted at Birmingham Crown Court last November.